Question

How do you find the zeros, if any, of `y= -x^2 -5x+2`using the quadratic formula?

Answer 1

Zeros are `x ~~ -5.37 , x~~ 0.37`

Explanation:

Quadratic equation is `y=ax^2 +bx+c`

`y= -x^2 -5x +2 ; a = -1 , b= -5 , c=2 ; D= b^2-4*a*c = 25 +8 =33 (+)`
Since D is positve, roots are real.

Roots are `x= -b/(2a)+- sqrt(b^2-4ac)/(2a) or x = 5/-2 +- sqrt 33/-2 or x= -2.5 +- (-2.87) :. x= -2.5 -2.87 ~~ -5.37 or x~~ 0.37` [Ans]