Please help! I will give 50 points and brainliest.

f(x) = (x^2 + 3x - 4)
g(x) = (x + 4)

a. Find f * g and state the domain
b. Find f / g and state the domain

Please explain your answer

Respuesta :

Answer:

Step-by-step explanation:

f * g = (x^2 + 3x - 4) (x+4)

open bracket

x((x^2 + 3x - 4) + 4 (x^2 + 3x - 4)

x³ +3x²-4x+x²+12x-16

x³+3x²+x²-4x+12x-16

x³+4x²+8x-16 (domain is all real numbers.

f/g = (x^2 + 3x - 4)/(x+4)

factorising (x^2 + 3x - 4)

x²+4x-x_4

x(x+4) -1 (x+4)

(x+4)(x-1)

f/g = (x^2 + 3x - 4)/(x+4) =(x+4)(x-1)/(x+4) = (x-1)

Before factorisation, this was a rational function so the domain is all real numbers excluding any value that would make the denominator equal zero.

Hence I got x - 1, and x cannot equal -4

 So the domain is just all real numbers without -4