Question

Given the function f(x) = x^2+3x+2 and g(x) = x+1,
determine a simplified equation for k(x)= f(g(x))

Answer 1

Do you know how to calculate f(2)? Just think of it the same way, but plug in g(x) instead.

Answer 2

k(x)= (x^2+3x+2)(x+1)


k(x)= x^3+4x^2+5x+2 <----- this the simplified answer?

Answer 3

Nope, what you're calculating is f(x)*g(x) but you want f(g(x)).

Answer 4

Pretend you want to calculate f(2) what's the first thing you do?

Answer 5

imput 2 in all the x values

Answer 6

Perfect, so if you want to calculate f(g(x)) then just input g(x) in all the x values.

Answer 7

i see... ok thanks, let me work it out

Answer 8

Sure, I'll tell you if you've done it right. =)

Answer 9

x^2+5x+4?

Answer 10

@kohai

Answer 11

f(x)=x^2+3x+2

so replacing all the x's with (x+1), since that's what g(x) is we get:

f(g(x))=(x+1)^2+3(x+1)+2

Does that make sense?

Answer 12

yah, ive done that, then i just added all like terms

Answer 13

oops i made an error in my calculations

Answer 14

x2+5x+6

Answer 15

x^2+5x+6 is my final answer @Kainui

Answer 16

Yeah perfect. Good job.

Answer 17

thanks you