Question

How do you find all real values of x such that f(x)=0?

Example 1: f(x)=15-3x

Example 2: f(x)= (12-x^2)/5

Example 3: f(X)= x^3 -x

Answer 1

HUH ?
set to 0

15 - 3 x = 0
3 x = 15
x = 5

12 - x^2 = 5*0 = 0
x^2 = 12
x = +/- sqrt 12 = +/- 2 sqrt 3

Answer 2

x^3 - x = 0

x (x^2-1) = 0

x (x-1)(x+1) = 0

x = 0
x = 1
x = -1