Does anyone have some practice problems for using functions within functions, like f(g(x))??

Question

anonymous · Answer

yes what is your question

unklerhaukus · Answer

anonymous · Answer

like just some problems?

anonymous · Answer

sure ask away :-)

anonymous · Answer

okay let me just make one up
f(x)= 3x
G(x)= x + 4

Is f(g(x))= 3x+12 and g(f(x)) 3x+7?

anonymous · Answer

Sure, here is a practice problem. What is g(f(x)) if f(x)=3x-5, g(x)=13. Tell me if you need more practice problems

unklerhaukus · Answer

@amcdowns

$$f(x)= 3x\qquad\qquad g(x)= x + 4$$

$$ f(g(x)) = 3(x+4) =3x+12 \checkmark$$but $$g(f(x)) 3x+7=(3x)+4=3x+4\checkmark\quad\neq3x+7$$?

anonymous · Answer

The f(g(x)) is correct, but the g(f(x)) is not correct, you would just have the answer to be 3x+4, there doesn't need to be a 7 in there.

anonymous · Answer

Okay thanks! So let me make another:
F(x)= 2x+8
g(x)= x+4

f(g(x))= 2x+16
g(f(x))= 2x+12

Are these right??

anonymous · Answer

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