Precalculus with Limits: A Graphing Approach, Sixth Edition
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Precalculus with Limits: A Graphing Approach, Sixth Edition View details
4. Solving Exponential and Logarithmic Equations
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Exercise 1 Page 217

To solve exponential and logarithmic equations, we employ the One-to-One and Inverse Properties of exponential and logarithmic functions. Let's complete the following proposition to represent one of these properties.

a^x = a^y if an only if .

Note that we have exponential expressions on one side of the given biconditional statement. Hence, this is one of the properties of exponential equations. a^x = a^y The given exponential expressions are equal to each other and they have the same base. Then, their exponents must also be equal. This is what the One-to-One Property of exponential functions tells us. a^x = a^y ⇒ x=y The converse of this statement is also true. If the exponents of two exponential expressions with the same base are equal, then the expressions themselves must be equal, too. x=y ⇒ a^x = a^y Let's write the biconditional statement. a^x = a^y ⇔ x=y We can now fill in the blank.

a^x = a^y if an only if x=y.

To solve exponential and logarithmic equations, we employ the One-to-One and Inverse Properties of exponential and logarithmic functions. Let's complete the following proposition to represent one of these properties.

log_a x=log_a y if an only if .

Note that we have logarithmic expressions on one side of the given biconditional statement. Hence, this is one of the properties of exponential equations. log_a x=log_a y The given logarithmic expressions are equal to each other and they have the same base. Then, their arguments must also be equal. This is what the One-to-One Property of logarithmic functions tells us. log_a x=log_a y ⇒ x=y The converse of this statement is also true. If the arguments of two logarithmic expressions with the same base are equal, then the expressions themselves must be equal, too. x=y ⇒ log_a x=log_a y Let's write the biconditional statement. log_a x=log_a y ⇔ x=y We can now fill in the blank.

log_a x=log_a y if an only if x=y.

Let's complete the following equation to represent one of the One-to-One and Inverse Properties specific to exponential and logarithmic functions.

a^(log_a x)= .

We have an exponential expression with a base a. Its exponent is a logarithmic expression with the same base a. In this case, they undo each other, resulting in the argument x of the logarithmic expression. a^(log_a x)=x This is what the Inverse Property of exponential functions tells us. We can now fill in the blank.

a^(log_a x)=x.

Let's complete the following equation to represent one of the One-to-One and Inverse Properties of exponential and logarithmic functions.

log_a a^x= .

We have a logarithmic expression with a base a. Its argument is an exponential expression with the same base a. In this case, they undo each other, resulting in the exponent x of the exponential expression. log_a a^x=x This is what the Inverse Property of logarithmic functions tells us. We can now fill in the blank.

log_a a^x=x.