1. ## sketching functions

hi, when it says to sketch (f o g)(x)

and $\displaystyle f(x) = x^2$ , $\displaystyle g(x) = 4x+3$

is that just $\displaystyle (4x+3)^2$ or $\displaystyle (4x+3)^2 \cdot x$ ?

cheers

2. Originally Posted by jvignacio
hi, when it says to sketch (f o g)(x)

and $\displaystyle f(x) = x^2$ , $\displaystyle g(x) = 4x+3$

is that just $\displaystyle (4x+3)^2$ or $\displaystyle (4x+3)^2 \cdot x$ ?

cheers
Its just the first one

fog is a fuction like f

When written as fog(x) its similar to writing f(x)

Its just the first one

fog is a fuction like f

When written as fog(x) its similar to writing f(x)
ahh yeah so we dont multiply (f o g) by x, just leave it as (f o g) , in this case $\displaystyle (4x+3)^2$ correct?

4. Originally Posted by jvignacio
ahh yeah so we dont multiply (f o g) by x, just leave it as (f o g) , in this case $\displaystyle (4x+3)^2$ correct?
yes it is

(fog)(x) = f(g(x))

5. Originally Posted by jvignacio
ahh yeah so we dont multiply (f o g) by x, just leave it as (f o g) , in this case $\displaystyle (4x+3)^2$ correct?
The notation f(x), with f a function, never means "multiply $\displaystyle f\cdot x$"!

6. Originally Posted by HallsofIvy
The notation f(x), with f a function, never means "multiply $\displaystyle f\cdot x$"!
yeah i know f(x) but i was confused with (f o g)(x) = f(g(x))