# Math Help - Function Notation help

1. ## Function Notation help

Just a stupid little question that I don’t understand how to solve, & would very much appreciate any kind of help, cheers.

$F(x)=2x^2+3x-1$

find in simplest form: $F(x+4)$

2. Originally Posted by jamaljenkins
Just a stupid little question that I don’t understand how to solve, & would very much appreciate any kind of help, cheers.

$F(x)=2x^2+3x-1$

find in simplest form: $F(x+4)$
just replace the $x$ in $F(x)$ with $x + 4$ and simplify

3. Pardon me for my idiocy, but the answer in the book is, $2x^2+19x+43$ & I don’t understand the step by step process of getting there

4. Originally Posted by jamaljenkins
Pardon me for my idiocy, but the answer in the book is, $2x^2+19x+43$ & I don’t understand the step by step process of getting there
$F(x) = 2x^2 + 3x - 1$

$\Rightarrow F(x + 4) = 2(x + 4)^2 + 3(x + 4) - 1$

now simplify, you do know how to, right?

5. i see where every number comes from through simplifying but could you for the purposes of progress, just do it for me?. It would be very appreciated.

6. Originally Posted by jamaljenkins
i see where every number comes from through simplifying but could you for the purposes of progress, just do it for me?. It would be very appreciated.
If it can be helped, we don't like doing people's work for them around here. It won't help you as much as if you tried it yourself.

$F(x + 4) = 2(x + 4)^2 + 3(x + 4) - 1$

............. $= 2 \left(x^2 + 8x + 16 \right) + 3x + 12 - 1$

............. $= 2x^2 + 16x + 32 + 3x + 11$

............. $= 2x^2 + 19x + 43$

Now that wasn't so hard was it?