# How do you find the roots, real and imaginary, of y=-15x^2 +40x -4  using the quadratic formula?

Jun 9, 2018

color(maroon)(" Roots are " x = 4/3 - sqrt(68/45), 4/3 + sqrt(68/45)

#### Explanation:

$y = - 15 {x}^{2} + 40 x - 4$

$x = \frac{- b \pm \sqrt{{b}^{2} - 4 a c}}{2 a}$

$a = - 15 , b = 40 , c = - 4$

$x = \frac{- 40 \pm \sqrt{1600 - 240}}{-} 30$

$x = \frac{- 40 \pm \sqrt{1360}}{-} 30$

color(maroon)("Roots are " x = 4/3 - sqrt(68/45), 4/3 + sqrt(68/45)