Question

Let f(x)=7-2x^2. Find the value of f(4+h).

Answer 1

\[ f(x)=7-2x^2.\]
\[f(x)=7-2(4+h)^2.\]

Answer 2

I know that but it has to be solved.

Answer 3

by "solved" i take it you mean multiply out and combine like terms right?

Answer 4

Yes, trying to work it out right now.

Answer 5

I typed it exactly as it says on the paper.

Answer 6

\[f(x)=7-2(4+h)^2\\
=7-2(4+h)(4+h)\] is a start

Answer 7

leave the -2 out front
\[7-2(16+8h+h^2)\] is the next step

Answer 8

then distribute the \(-2\)

Answer 9

So you foil after squaring? That is the part I always get confused at.

Answer 10

ok lets go slow

Answer 11

squaring means to multiply by itself
so \[(a+b)^2=(a+b)(a+b)\] and
\[(4+h)^2=(4+h)(4+h)\]

Answer 12

Yeah, I think I got it

Answer 13

it is always the case that
\[(a+b)^2=a^2+2ab+b^2\]

Answer 14

Answer is -25-16h-2h^2

Answer 15

ok if you say so

Answer 16

Or better written as -2h^2-16h-15

Answer 17

yeah looks good to me

Answer 18

btw i see in your profile that you are majoring in education
do me a huge favor please
do not every tell students to "solve" unless you are solving an equation
what you are doing here is not solving, it is writing in standard form
and don't even get me started on "foil"

Answer 19

LOL. majoring in early childhood/special education. Likely hood of needing to do/teach this is slim.