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

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Answer 1 · 2018-06-09T09:17:36

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

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

$x = (-b +- sqrt(b^2 - 4ac)) / (2a)$

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

$x = (-40 +- sqrt(1600 - 240)) / -30$

$x = (-40 +- sqrt1360) / - 30$

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

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