Question

Find (f • g)(x) for f(x) = x + 7 and g(x) = x – 3

Answer 1

so just sub g into f

so you want

f(g(x))

Answer 2

that dot means to sub the one function into the other function

Answer 3

do you just want me to show you or do you follow?

Answer 4

I'm pretty sure that dot means multiplication:

(f • g)(x) = f(x) • g(x) = (x+7) • (x-3)
Don't confuse (f • g)(x) with (f o g)(x)

Answer 5

oh yeah you are right hero

Answer 6

still kinda confused

Answer 7

Why? It's pretty obvious to multiply (x+7)(x-3)

Answer 8

yeah unless it the dot is hollow then it is composition of functions

Answer 9

I just dont like the use of dots for multiplication because of their use in vectors

Answer 10

or linear algebra rather

Answer 11

do foil?

Answer 12

or just 7x3?

Answer 13

Do distributive rule

(x+7)(x-3) = x(x-3) + 7(x-3) = x^2 - 3x + 7x - 21 = x^2 +4x - 21

Answer 14

FOIL is an acronym not a mathematical property

Answer 15

ok