Solve Log_9 V + Log_9 9 = 1 Simplify The Answer

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#h1 Solve the Logarithmic Equation log9v+log99=1\log _9 v+\log _9 9=1

In the realm of mathematics, solving logarithmic equations is a fundamental skill. Logarithmic equations are equations in which the variable appears in the argument (the input) of a logarithm. To solve these equations, we often use the properties of logarithms to simplify the equation and isolate the variable. In this article, we will delve into the process of solving the logarithmic equation log9v+log99=1\log _9 v+\log _9 9=1, simplifying the answer, and understanding the underlying principles involved. Logarithmic equations play a crucial role in various fields, including science, engineering, and finance, making it essential to master the techniques for solving them. This article provides a step-by-step guide to solving the given equation and emphasizes the importance of simplifying the solution to its most basic form.

The given logarithmic equation is:

log9v+log99=1\log _9 v+\log _9 9=1

Our goal is to find the value of v that satisfies this equation. To achieve this, we will employ the properties of logarithms to combine the logarithmic terms and isolate v. The key property we'll use here is the product rule of logarithms, which states that the logarithm of the product of two numbers is equal to the sum of the logarithms of the individual numbers. In mathematical notation, this is expressed as:

logb(mn)=logb(m)+logb(n)\log_b(mn) = \log_b(m) + \log_b(n)

where b is the base of the logarithm, and m and n are positive numbers. Understanding this property is crucial for simplifying logarithmic expressions and solving equations involving logarithms. It allows us to combine multiple logarithmic terms into a single term, making the equation easier to manipulate and solve. By applying the product rule, we can transform the given equation into a simpler form that is more amenable to solving for v. This step is essential in the overall process of finding the solution to the logarithmic equation.

Step-by-step Solution

  1. Apply the Product Rule of Logarithms:

    The product rule of logarithms states that logb(m)+logb(n)=logb(mn)\log_b(m) + \log_b(n) = \log_b(mn). Applying this rule to our equation, we combine the two logarithmic terms:

    log9v+log99=log9(vimes9)\log _9 v+\log _9 9 = \log _9 (v imes 9)

    So the equation becomes:

    log9(9v)=1\log _9 (9v) = 1

    This step is crucial as it simplifies the equation by combining two logarithmic terms into one, making it easier to isolate the variable. The product rule is a fundamental property of logarithms that allows us to manipulate logarithmic expressions and solve equations involving logarithms. By applying this rule, we transform the original equation into a more manageable form, paving the way for the next steps in the solution process. This transformation is a key step in solving logarithmic equations, as it reduces the complexity of the equation and makes it easier to work with.

  2. Convert the Logarithmic Equation to Exponential Form:

    To eliminate the logarithm, we convert the equation from logarithmic form to exponential form. The general form for this conversion is:

    If logb(x)=y\log_b(x) = y, then by=xb^y = x

    Applying this to our equation log9(9v)=1\log _9 (9v) = 1, we get:

    91=9v9^1 = 9v

    Converting to exponential form is a fundamental step in solving logarithmic equations. It allows us to remove the logarithm and express the equation in a form that is easier to manipulate algebraically. The exponential form directly relates the base of the logarithm, the argument, and the result, providing a clear path to isolating the variable. This conversion is based on the definition of logarithms, which states that the logarithm of a number to a given base is the exponent to which the base must be raised to produce that number. By converting to exponential form, we transform the equation into a familiar algebraic form that we can easily solve.

  3. Solve for v:

    Now we have the equation:

    9=9v9 = 9v

    To isolate v, we divide both sides of the equation by 9:

    99=9v9\frac{9}{9} = \frac{9v}{9}

    1=v1 = v

    Therefore, v = 1.

    Isolating the variable is the final step in solving the equation. By performing algebraic operations on both sides of the equation, we can isolate v and determine its value. In this case, we divided both sides by 9 to isolate v. This step is crucial in finding the solution to the equation and completing the problem. The result, v = 1, is the value that satisfies the original logarithmic equation. This final step demonstrates the importance of algebraic manipulation in solving equations and arriving at the correct solution.

Simplify the Answer

In this case, our solution v = 1 is already in its simplest form. There are no further simplifications needed. It's a whole number and cannot be reduced further.

Simplifying the answer is an important step in solving mathematical problems. It ensures that the solution is presented in its most concise and understandable form. In some cases, simplification may involve reducing fractions, combining like terms, or expressing the answer in a different notation. However, in this case, the solution v = 1 is already in its simplest form, as it is a whole number and cannot be reduced further. This highlights the importance of recognizing when a solution is already in its simplest form and avoiding unnecessary steps. The goal of simplification is to present the solution in a way that is easy to interpret and use in further calculations or applications.

Verification of the Solution

To ensure the correctness of our solution, we substitute v = 1 back into the original equation:

log9v+log99=1\log _9 v+\log _9 9=1

log9(1)+log99=1\log _9 (1)+\log _9 9=1

We know that logb(1)=0\log_b(1) = 0 for any base b, so log9(1)=0\log _9 (1) = 0. Also, log99=1\log _9 9 = 1 because 91=99^1 = 9. Substituting these values, we get:

0+1=10 + 1 = 1

1=11 = 1

Since the equation holds true, our solution v = 1 is correct.

Verifying the solution is a critical step in the problem-solving process. It ensures that the solution obtained satisfies the original equation and that no errors were made during the solution process. By substituting the solution back into the original equation, we can check whether the equation holds true. If the equation holds true, then the solution is correct. If the equation does not hold true, then an error was made, and we need to review the steps taken to solve the equation. In this case, substituting v = 1 back into the original equation resulted in a true statement, confirming that our solution is correct. This step reinforces the importance of verification in ensuring the accuracy of our results.

Conclusion

We have successfully solved the logarithmic equation log9v+log99=1\log _9 v+\log _9 9=1 and found the solution to be v = 1. We achieved this by applying the product rule of logarithms, converting the equation to exponential form, and solving for v. We also verified our solution to ensure its accuracy.

In conclusion, mastering the solution of logarithmic equations is a crucial skill in mathematics. Logarithmic equations appear in various contexts, and understanding how to solve them is essential for success in mathematics and related fields. This article has provided a step-by-step guide to solving the given equation, emphasizing the importance of understanding the properties of logarithms and applying them correctly. By practicing these techniques, you can develop confidence in your ability to solve logarithmic equations and tackle more complex problems. The ability to solve logarithmic equations is not only valuable in academic settings but also in real-world applications, making it a valuable skill to acquire.

#h2 Understanding Logarithmic Equations

Understanding logarithmic equations is essential for anyone studying mathematics or related fields. Logarithms are the inverse operations of exponentiation, and logarithmic equations involve solving for an unknown variable within a logarithmic expression. In this section, we will explore the basics of logarithmic equations, including their definition, properties, and the relationship between logarithmic and exponential forms. This foundational knowledge is crucial for solving logarithmic equations and understanding their applications in various fields. By grasping the fundamentals of logarithmic equations, you will be well-equipped to tackle more complex problems and appreciate the power of logarithms in mathematics.

A logarithmic equation is an equation that contains a logarithm. The general form of a logarithmic equation is:

logb(x)=y\log_b(x) = y

where b is the base of the logarithm, x is the argument, and y is the result. The logarithm logb(x)\log_b(x) represents the exponent to which b must be raised to obtain x. In other words, if logb(x)=y\log_b(x) = y, then by=xb^y = x. This relationship between logarithmic and exponential forms is fundamental to understanding and solving logarithmic equations.

The base of a logarithm is a positive number not equal to 1. The argument of a logarithm must be a positive number. These restrictions are important to keep in mind when solving logarithmic equations, as they can affect the domain of the equation and the validity of the solutions. Understanding these restrictions is crucial for avoiding errors and ensuring that the solutions obtained are meaningful.

Logarithmic equations can take various forms, including equations with a single logarithm, equations with multiple logarithms, and equations involving other mathematical operations. Solving these equations often involves using the properties of logarithms to simplify the equation and isolate the variable. The properties of logarithms provide a set of rules for manipulating logarithmic expressions, allowing us to combine, expand, and simplify them. These properties are essential tools for solving logarithmic equations and will be discussed in more detail later in this section.

Key Properties of Logarithms

Several key properties of logarithms are essential for solving logarithmic equations. These properties allow us to manipulate logarithmic expressions and simplify equations. Here are some of the most important properties:

  1. Product Rule:

    logb(mn)=logb(m)+logb(n)\log_b(mn) = \log_b(m) + \log_b(n)

    This rule states that the logarithm of the product of two numbers is equal to the sum of the logarithms of the individual numbers. The product rule is a fundamental property of logarithms that allows us to combine logarithmic terms and simplify equations. It is particularly useful when dealing with equations that involve the logarithm of a product.

  2. Quotient Rule:

    logb(mn)=logb(m)logb(n)\log_b(\frac{m}{n}) = \log_b(m) - \log_b(n)

    This rule states that the logarithm of the quotient of two numbers is equal to the difference of the logarithms of the individual numbers. The quotient rule is another important property of logarithms that allows us to simplify equations involving the logarithm of a quotient. It is the counterpart of the product rule and is equally useful in solving logarithmic equations.

  3. Power Rule:

    logb(mp)=plogb(m)\log_b(m^p) = p \log_b(m)

    This rule states that the logarithm of a number raised to a power is equal to the power multiplied by the logarithm of the number. The power rule is a powerful tool for simplifying logarithmic expressions and solving equations that involve exponents. It allows us to move exponents out of the argument of the logarithm, making the equation easier to solve.

  4. Change of Base Rule:

    logb(m)=logc(m)logc(b)\log_b(m) = \frac{\log_c(m)}{\log_c(b)}

    This rule allows us to change the base of a logarithm. It is particularly useful when dealing with logarithms with different bases. The change of base rule enables us to express logarithms in terms of a common base, making it easier to compare and manipulate them. This rule is essential when using calculators to evaluate logarithms with bases other than 10 or e.

  5. Logarithm of 1:

    logb(1)=0\log_b(1) = 0

    The logarithm of 1 to any base is always 0. This property is a direct consequence of the definition of logarithms, as any number raised to the power of 0 is equal to 1. This property is useful for simplifying logarithmic expressions and solving equations.

  6. Logarithm of the Base:

    logb(b)=1\log_b(b) = 1

    The logarithm of the base to itself is always 1. This property is also a direct consequence of the definition of logarithms, as any number raised to the power of 1 is equal to itself. This property is another useful tool for simplifying logarithmic expressions and solving equations.

These properties are essential tools for solving logarithmic equations. By understanding and applying these properties, you can simplify complex logarithmic expressions and equations, making them easier to solve. Mastering these properties is crucial for success in solving logarithmic equations and understanding their applications.

Converting Between Logarithmic and Exponential Forms

The relationship between logarithmic and exponential forms is fundamental to solving logarithmic equations. The logarithmic form logb(x)=y\log_b(x) = y is equivalent to the exponential form by=xb^y = x. Understanding this equivalence is crucial for converting between the two forms and solving equations.

To convert from logarithmic form to exponential form, we use the definition of logarithms. The logarithm logb(x)\log_b(x) represents the exponent to which b must be raised to obtain x. Therefore, if logb(x)=y\log_b(x) = y, then by=xb^y = x. This conversion allows us to eliminate the logarithm and express the equation in a form that is easier to manipulate algebraically.

To convert from exponential form to logarithmic form, we use the same relationship in reverse. If by=xb^y = x, then logb(x)=y\log_b(x) = y. This conversion allows us to introduce logarithms into an equation, which can be useful for solving equations involving exponents.

Converting between logarithmic and exponential forms is a fundamental skill for solving logarithmic equations. It allows us to manipulate equations and express them in a form that is easier to solve. This skill is essential for mastering logarithmic equations and their applications.

Common Logarithms and Natural Logarithms

Two common types of logarithms are the common logarithm and the natural logarithm. The common logarithm is the logarithm with base 10, denoted as log10(x)\log_{10}(x) or simply log(x)\log(x). The natural logarithm is the logarithm with base e, where e is the mathematical constant approximately equal to 2.71828, denoted as loge(x)\log_e(x) or ln(x)\ln(x).

Common logarithms are widely used in science and engineering, particularly in applications involving scientific notation and orders of magnitude. Natural logarithms are prevalent in calculus and other areas of mathematics, as they have convenient properties for differentiation and integration. Understanding common and natural logarithms is essential for working with logarithms in various contexts.

Most calculators have built-in functions for evaluating common and natural logarithms. These functions make it easy to calculate the values of logarithms and solve logarithmic equations. When using a calculator to evaluate logarithms with bases other than 10 or e, the change of base rule can be used to convert the logarithm to a common or natural logarithm.

In summary, understanding logarithmic equations involves grasping their definition, properties, and the relationship between logarithmic and exponential forms. The key properties of logarithms, such as the product rule, quotient rule, and power rule, are essential tools for solving logarithmic equations. Converting between logarithmic and exponential forms is a fundamental skill, and understanding common and natural logarithms is important for working with logarithms in various contexts. With a solid understanding of these concepts, you will be well-prepared to solve logarithmic equations and apply them in various fields.

#h3 Techniques for Solving Logarithmic Equations

Techniques for solving logarithmic equations involve a systematic approach to isolate the variable and find its value. Logarithmic equations can appear in various forms, and mastering different techniques is crucial for solving them efficiently. In this section, we will delve into the common techniques used to solve logarithmic equations, including simplifying the equation, converting to exponential form, and dealing with multiple logarithms. Understanding these techniques will empower you to tackle a wide range of logarithmic equations and apply them in various contexts. This section serves as a comprehensive guide to the methods used to solve logarithmic equations, ensuring that you have a strong foundation in this essential mathematical skill.

Solving logarithmic equations typically involves the following steps:

  1. Simplify the Equation:

    The first step in solving a logarithmic equation is to simplify it as much as possible. This may involve using the properties of logarithms to combine or expand logarithmic terms. For example, the product rule can be used to combine the sum of logarithms into a single logarithm, and the power rule can be used to move exponents out of the argument of the logarithm. Simplifying the equation makes it easier to isolate the variable and solve for its value. This step is crucial in reducing the complexity of the equation and making it more manageable.

  2. Convert to Exponential Form:

    Once the equation is simplified, the next step is to convert it from logarithmic form to exponential form. This involves using the relationship between logarithms and exponents, which states that logb(x)=y\log_b(x) = y is equivalent to by=xb^y = x. Converting to exponential form eliminates the logarithm and expresses the equation in a form that is easier to manipulate algebraically. This step is essential in solving logarithmic equations, as it allows us to remove the logarithm and work with a more familiar algebraic form.

  3. Solve for the Variable:

    After converting to exponential form, the equation can be solved for the variable using standard algebraic techniques. This may involve isolating the variable on one side of the equation by performing operations such as addition, subtraction, multiplication, or division. The goal is to find the value of the variable that satisfies the equation. This step is the culmination of the solution process, where we apply algebraic techniques to determine the value of the unknown variable.

  4. Check for Extraneous Solutions:

    It is important to check the solution(s) obtained by substituting them back into the original logarithmic equation. Logarithmic functions have a restricted domain, meaning that the argument of the logarithm must be positive. Solutions that do not satisfy this condition are called extraneous solutions and must be discarded. Checking for extraneous solutions is a crucial step in solving logarithmic equations, as it ensures that the solutions obtained are valid and meaningful.

Dealing with Multiple Logarithms

Equations with multiple logarithms can be solved by using the properties of logarithms to combine the logarithmic terms into a single logarithm. This often involves using the product rule, quotient rule, or power rule to simplify the equation. Once the equation has been simplified to a single logarithm, it can be converted to exponential form and solved for the variable.

For example, consider the equation:

logb(x)+logb(y)=z\log_b(x) + \log_b(y) = z

Using the product rule, we can combine the two logarithmic terms into a single logarithm:

logb(xy)=z\log_b(xy) = z

Now, we can convert to exponential form:

bz=xyb^z = xy

If we are solving for x, we can divide both sides by y:

x=bzyx = \frac{b^z}{y}

This example illustrates how the properties of logarithms can be used to simplify equations with multiple logarithms and solve for the variable. The ability to combine logarithmic terms is a powerful tool for solving logarithmic equations and is essential for mastering this type of problem.

Solving Equations with Logarithms on Both Sides

Equations with logarithms on both sides can be solved by using the properties of logarithms to combine the logarithmic terms and eliminate the logarithms. This often involves using the one-to-one property of logarithms, which states that if logb(x)=logb(y)\log_b(x) = \log_b(y), then x = y. By applying this property, we can eliminate the logarithms and solve the resulting algebraic equation.

For example, consider the equation:

logb(x+1)=logb(2x3)\log_b(x + 1) = \log_b(2x - 3)

Using the one-to-one property of logarithms, we can eliminate the logarithms:

x+1=2x3x + 1 = 2x - 3

Now, we can solve for x:

x=4x = 4

It is important to check the solution by substituting it back into the original equation to ensure that it is not an extraneous solution. In this case, x = 4 is a valid solution.

This example demonstrates how the one-to-one property of logarithms can be used to solve equations with logarithms on both sides. This technique is a valuable tool for solving logarithmic equations and is essential for mastering this type of problem.

Using the Definition of Logarithms

In some cases, it may be helpful to use the definition of logarithms directly to solve a logarithmic equation. The definition of logarithms states that if logb(x)=y\log_b(x) = y, then by=xb^y = x. By applying this definition, we can convert the logarithmic equation to an exponential equation and solve for the variable.

For example, consider the equation:

log2(x)=3\log_2(x) = 3

Using the definition of logarithms, we can convert this to:

23=x2^3 = x

So, x = 8.

This example illustrates how the definition of logarithms can be used to solve logarithmic equations. This technique is particularly useful when dealing with simple logarithmic equations or when the properties of logarithms are not easily applicable.

Extraneous Solutions

When solving logarithmic equations, it is important to check for extraneous solutions. Extraneous solutions are solutions that satisfy the transformed equation but do not satisfy the original logarithmic equation. This can occur because the domain of a logarithmic function is restricted to positive numbers. Therefore, any solution that results in a negative or zero argument in the original logarithmic equation is an extraneous solution and must be discarded.

To check for extraneous solutions, substitute each solution back into the original logarithmic equation and verify that the argument of the logarithm is positive. If the argument is not positive, then the solution is extraneous and must be discarded.

In summary, solving logarithmic equations involves a systematic approach that includes simplifying the equation, converting to exponential form, solving for the variable, and checking for extraneous solutions. Techniques for dealing with multiple logarithms and equations with logarithms on both sides are essential for solving a wide range of logarithmic equations. By mastering these techniques, you will be well-prepared to tackle logarithmic equations and apply them in various contexts.