Question

What element in the domain has image 7 in the function f(x) = x²– 2?

a. 3 b) 9 c) -1 d) 4

Answer 1

`f(x) = 7 \\ f(x) = {x}^(2) - 2 \\ {x}^(2) - 2 = 7 \\ {x}^(2) = 2 + 7 \\ {x}^(2) = 9 \\ x = √(9) \\ \boxed{x = 3}`

Therefore, 3 is the element in the domain which has the image 7 in function f(x)=x²-2

• A. 3 is the right answer.