Precalculus : Functions

Study concepts, example questions & explanations for Precalculus

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Example Questions

Example Question #4 : Composition Of Functions

For the functions

and

.

Evaluate the composite function

.

Possible Answers:

DNE

Correct answer:

Explanation:

The composite function means to plug in the function  into  for every x value.

Therefore the composite function becomes,

Example Question #4 : Composition Of Functions

If , and , what is ?

Possible Answers:

Correct answer:

Explanation:

When doing a composition of functions such as this one, you must always remember to start with the innermost parentheses and work backward towards the outside.

So, to begin, we have

 .

Now we move outward, getting 

.

Finally, we move outward one more time, getting 

.

Example Question #3 : Composition Of Functions

Find  if  , and .

Possible Answers:

Correct answer:

Explanation:

Solve for the value of .

Solve for the value of .

Solve for the value .

Example Question #8 : Composition Of Functions

For the functions  and , evaluate the composite function  

Possible Answers:

Correct answer:

Explanation:

The composite function notation  means to swap the function  into  for every value of . Therefore:

Example Question #5 : Composition Of Functions

For the functions  and , evaluate the composite function 

Possible Answers:

Correct answer:

Explanation:

The composite function notation  means to swap the function  into  for every value of . Therefore:

Example Question #10 : Composition Of Functions

For the functions  and , evaluate the composite function .

Possible Answers:

None of the answers listed

Correct answer:

Explanation:

The composite function notation  means to swap the function  into  for every value of . Therefore:

Example Question #161 : Functions

Let

Determine .

Possible Answers:

Correct answer:

Explanation:

To find the composite function we start from the most inner portion of the expression and work our way out.

Example Question #162 : Functions

Let

Determine 

.

Possible Answers:

Correct answer:

Explanation:

The composite funtion means to replace every entry x in f(x) with the entire function g(x).

Example Question #11 : Composition Of Functions

For , , and , determine .

Possible Answers:

Correct answer:

Explanation:

Working inside out, first do .

This is,

 .

Now we will do .

This is

Example Question #14 : Composition Of Functions

For , write a function for .

Possible Answers:

Correct answer:

Explanation:

Working from the inside out, first we will find a function for .

This is:

, which we can simplify slightly to .

Now we will plug this new function into the function k:

.

Since ln is the inverse of e to any power, this simplifies to .

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