#1

ok so i just joined this pre-calc class Friday and im kind of lost. im getting some of it right but im never sure with this so of. Were doing composite functions. Here’s the problem.

Find (FoG) and (GoF)

F (x)= x^3

G (x)= x+1

Here’s how i think u solve (FoG)

X (x+1)^3 with equal’s x4+3x3+3x2+x

again not sure if right. plz help

Find (FoG) and (GoF)

F (x)= x^3

G (x)= x+1

Here’s how i think u solve (FoG)

X (x+1)^3 with equal’s x4+3x3+3x2+x

again not sure if right. plz help

*Last edited by pawnshop_1919 at Sep 9, 2007,*

#2

FoG means plug in the function G wherever you see x in F.

So FoG would be 3(x+1) = 3x + 3

and GoF means plug in the function F wherever you see x in G.

So GoF would be (3x) + 1 = 3x + 1

So FoG would be 3(x+1) = 3x + 3

and GoF means plug in the function F wherever you see x in G.

So GoF would be (3x) + 1 = 3x + 1

#3

Fog and Gof, what exactly do you mean by that

#4

where did u get the 3. its to the x to the 3rd power.

#5

We did that in Algebra 2 last year. I'm in Pre-Calc now though, and I think darkstar is right.

#6

Haha. I have the same class, and we just learned that last week.

(FoG) would be (x+1)^3

(GoF) would be (x^3)+1.

I'm pretty sure.

(FoG) would be (x+1)^3

(GoF) would be (x^3)+1.

I'm pretty sure.

#7

where did u get the 3. its to the x to the 3rd power.

Then you f*cking say x^3. Not x3.

#8

Then you f*cking say x^3. Not x3.

i know my bad. i didnt see it tilll after i post it

#9

1st of all that isnt even precalc second of all that is really simple

#10

Then FoG would be (x+1)^3 = x^3 + 3x^2 + 3x + 1

and GoF would be x^3 + 1.

and GoF would be x^3 + 1.

#11

1st of all that isnt even precalc second of all that is really simple

It is something you learn in precalc, dumbass. Have you looked at a precalc textbook recently?

#12

if F(x)=x^3, then:

FoG=(x+1)^3

=(x+1)(x^2+2x+1)

=x^3+2x^2+x+x^2+2x+1

=X^3+3x^3+3x+1

FoG=(x+1)^3

=(x+1)(x^2+2x+1)

=x^3+2x^2+x+x^2+2x+1

=X^3+3x^3+3x+1

#13

Then FoG would be (x+1)^3 = x^3 + 3x^2 + 3x + 1

and GoF would be x^3 + 1.

Correct.

#14

yes i am in precalc....and i learned that in my algebra book

#15

In Calculus, you will apply this chain rule to do differentiation.

#16

ok thx. i dont know why i put the X on outside of the equation

thx again darkstar2466 and everyone else. even the jackasses

thx again darkstar2466 and everyone else. even the jackasses