Question

Which two values of xare roots of the polynomial below?
5x^2-5x+1

Answer 1

Explanation:

can't factor so can use quadratic

5 +/- √(25-20)/10

(5+√5)/10

(5-√5)/10

Answer 2

Explanation:

Apply the quadratic formula. The coefficients are {5, -5, 1}. The discriminant is b^2 - 4ac, which here works out to 25 - 4(5)(1), or 5. This positive result tells us that this quadratic has two unequal, real roots. These roots are:

-(-5) ± √5 5 ± √5

x = --------------- = -------------

10 10