Hi, there--
.
The Problem:
For the function f defined by f(x)=4x^2+5x+9, find the following values:
a. f(-2)=
b. f(-x)=
c.-f(x)=
d. f(x+h)=

Solution:
These are actually much easier to do than you might think. One challenging part can be 
dealing with the negative signs. Let's start with the first one.

a. Find f(-2)

Start with the function f and substitute -2 for x in the right hand side.



Clear the parentheses on the right hand side; (-2) squared is 4 because (-2)(-2)=4.



Add the constant terms on the right hand side.


I'll set up the others for you. 

b.
Remember that (-x) squared is x^2.

c. 
Distribute the negative sign across every term on the right hand side.

d. 
This is the most complex substitution of the set. However, if you plan to take calculus, the f(x+h) 
substitution is one you will do A LOT...good to practice now.

Try these on your own. Email me if you have questions or if you want me to check your answers.

Ms.Figgy
math.in.the.vortex@gmail.com