How do you find the roots, real and imaginary, of y= -5x^2 +5x-2 using the quadratic formula?

1 Answer
Shwetank Mauria
Feb 18, 2016

Roots are complex conjugate pair x=(5+isqrt15)/10 and (5-isqrt15)/10

Explanation:

By finding the roots, real and imaginary, of y=−5x^2+5x−2, means finding zeros of the function y=−5x^2+5x−2 or solving the equation −5x^2+5x−2=0.

The solution of equation ax^2+bx+c=0 are given by x=((-b+-sqrt(b^2-4ac))/(2a)).

As a=-5, b=5 and c=-2,

x=((-5+-sqrt((-5)^2-4*(-5)*(-2)))/(2(-5))).or

x=((-5+-sqrt(25-40))/(-10)) or

x=((5+-sqrt(-15))/10) or

x=((5+-isqrt15)/10)

Hence, roots are complex conjugate pair (5+isqrt15)/10 and x=(5-isqrt15)/10

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