Question

If f : R R is defined by f(x) =2x 2

-1. Find the pre-image of 17, 4 and -2​

Answer 1

Answer:

The pre image of 17

2x^2-1 =17

2x^2=18

x^2=18/2

x^2=9

Therefore x= 3 , -3

The pre image of 4

2x^2-1= 4

2x^2=5

x^2 = 5/2

Therefore x= √5/2 , -√5/2

The pre image of -2

2x^2-1=-2

2x^2= -1

x^2 = -1/2