Question

F(x)=2x^2-5;find when f(x)=-7​

Answer 1

x=i or no solution exists depending on the user's grade

Explanation:

f(x) = 2x^2-5

-7 = 2x^2-5

-2 = 2x^2, x^2=-1, x=i

Answer 2

±i = x

Explanation:

f(x)=2x^2-5;

f(x)=-7​

-7 = 2x^2 -5

Add 5 to each side

-7+5 = 2x^2 -5+5

-2 =2x^2

Divide by 2

-2/2 =2x^2 /2

-1 = x^2

Take the square root of each side

sqrt(-1) = sqrt(x^2)

±i = x