Question

Calculate the following composition function using the functions f and g defined below:

f:N→N, f(x) = x + 5 and g:N→N, g(x) = 5x – 3

(f∘g)(x)

Answer 1

How do I calculate the value of these function without an x value?

Answer 2

@freckles

Answer 3

f∘g (x) = f ( g(x) )
treat 'g(x)' as the new x . plug it into f
f( x) = x + 5

f ( g(x) ) =g(x)+5

replace g(x) by 5x-3
(5x-3) + 5
simplify
5x + 2

Answer 4

Does that make sense?

Answer 5

@freckles is this explanation correct?

Answer 6

@jim_thompson5910 is this explanation correct?

Answer 7

let me check

Answer 8

jayzdd has the right explanation

Answer 9

The online quiz I took said 5x+22; but, I think it was a mistake.

Answer 10

there has to be a typo

Answer 11

I'm also trying to figure out where my algebra went wrong on this problem: f(x) = 2x, g(x) = (x-1)/2

I did 2(x-1)/2))
Then 2x-2/2
Finally x-1

The answer this quiz gives me is x-1/2

Answer 12

They give you `f(x) = 2x, g(x) = (x-1)/2` what exactly are you trying to find? or compute?

Answer 13

The following functions map ℝ to ℝ. Give an equation describing the composition function g∘f:

f(x) = 2x, g(x) = (x-1)/2