Question

VERY confused:
f(x)=3x
g(x)=x-3

and h(x)= vTx

What is (fogoh)(25)

isn't it
3(x-3)

3x-3
? Then I don't know what to do!

Answer 1

h = what?

Answer 2

Oh, that's how I write the square root of x haha, sorry.

Answer 3

so take it step by step... what is the innermost fucntion? what's next innermost? what's the outermost?

\[\left( f \circ g \circ h \right)\left( x \right)=f \left( g \left( h \left( x \right) \right) \right)\]
start plugging in the innermost...\[\left( f \circ g \circ h \right)\left( 25 \right)=f \left( g \left( h \left( 25 \right) \right) \right)\]

Answer 4

okay, then I plug in h right?

Answer 5

\[f(g (\sqrt{x}(25)))\]

Answer 6

close...
\[f \left( g \left( \sqrt{25} \right) \right)\]

Answer 7

remember, x = 25

Answer 8

Okay now G, correct?

Answer 9

\[\sqrt{25}-3\]

Answer 10

so what is h(25)? it's best to simplify as you go...

you should also see if you can come up with (f o g o h)(x) by itself and then plug in x = 25 to check that you get the same number.

Answer 11

Oh it's 5 haha, whoops.

Answer 12

so do I do 5-3, and then multiply that by 3?

Answer 13

you know it!

Answer 14

good luck, got to go!