SAT II Math I : Solving Exponential Functions

Study concepts, example questions & explanations for SAT II Math I

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Example Questions

Example Question #1 : Solving Exponential Equations

Solve for :

Possible Answers:

No solution

Correct answer:

Explanation:

125 and 25 are both powers of 5.

Therefore, the equation can be rewritten as 

.

Using the Distributive Property, 

Since both sides now have the same base, set the two exponents equal to one another and solve:

Add 30 to both sides: 

Add  to both sides: 

Divide both sides by 20: 

Example Question #7 : Solving Exponential Equations

Solve .

Possible Answers:

No solution

Correct answer:

Explanation:

Both 27 and 9 are powers of 3, therefore the equation can be rewritten as 

.

Using the Distributive Property, 

Now that both sides have the same base, set the two exponenents equal and solve.

Add 12 to both sides: 

Subtract  from both sides: 

Example Question #8 : Solving Exponential Equations

Possible Answers:

Correct answer:

Explanation:

The first step in thist problem is divide both sides by three: . Then, recognize that 8 could be rewritten with a base of 2 as well (). Therefore, your answer is 3.

Example Question #9 : Solving Exponential Equations

Solve for .

Possible Answers:

Correct answer:

Explanation:

Let's convert  to base .

We know the following:

Simplify.

Solve.

 

Example Question #10 : Solving Exponential Equations

Solve for .

Possible Answers:

Correct answer:

Explanation:

Let's convert  to base .

We know the following:

Simplify.

Solve.

.

Example Question #11 : Solving Exponential Equations

Solve for .

Possible Answers:

Correct answer:

Explanation:

When multiplying exponents with the same base, we will apply the power rule of exponents:

We will simply add the exponents and keep the base the same.

Example Question #11 : Solving Exponential Equations

Solve for .

Possible Answers:

Correct answer:

Explanation:

When multiplying exponents with the same base, we will apply the power rule of exponents:

We will simply add the exponents and keep the base the same.

Simplify.

Solve.

Example Question #13 : Solving Exponential Equations

Solve for .

Possible Answers:

Correct answer:

Explanation:

When adding exponents with the same base, we need to see if we can factor out the numbers of the base.

In this case, let's factor out .

We get the following:

Since we are now multiplying with the same base, we get the following expression:

Now we have the same base and we just focus on the exponents.

The equation is now:

Solve.

Example Question #14 : Solving Exponential Equations

Solve for .

Possible Answers:

Correct answer:

Explanation:

First, we need to convert  to base .

We know .

Therefore we can write the following expression:

.

Next, when we add exponents of the same base, we need to see if we can factor out terms.

In this case, let's factor out .

We get the following: 

.

Since we are now multiplying with the same base, we get the following expression:

.

Now we have the same base and we just focus on the exponents.

The equation is now:

Solve.

Example Question #1 : Graphing Exponential Functions

Give the -intercept of the graph of the equation .

Possible Answers:

The graph has no -intercept.

Correct answer:

The graph has no -intercept.

Explanation:

Set  and solve for 

We need not work further. It is impossible to raise a positive number 2 to any real power to obtain a negative number. Therefore, the equation has no solution, and the graph of  has no -intercept. 

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