Question

how to I define and find values for:
f(x)=4x^2+5x+8
f(-1)
f(-x)
-f(x)
f(xh)

Answer 1

f(-1) -> substitute all x with -1
f(-x) -> change all x into -x
-f(x) take the negative of the equation
f(xh) change all the x into xh

do you need more help? :)

Answer 2

can you do 1 example for me?

Answer 3

okay let's try f(-1)

like i said substitute all x into -1 so you have

4(-1)^2 + 5(-1) + 8
4(1) - 5 + 8
4 - 5 + 8
-1 + 8
7

Answer 4

did you get that?

Answer 5

ok, yes...

Answer 6

good..so can you do f(-x)?

Answer 7

The problem would be set up as: 4(-x)^2+5(-x)+8

Answer 8

correct! now simplify :)

Answer 9

4(-x)-5-8
4-5-8
-x-8
Is this correct?

Answer 10

hmm not exactly...

4(-x)^2 = 4x^2

5(-x) = -5x

Answer 11

I got 4x^2-5x+8

Answer 12

correct! :D

Answer 13

Thank you so much!

Answer 14

<tips hat>

Answer 15

do you know how to get -f(x) and f(xh)?