Solve the Quadratic Equation by hand

Question

y=-2x^2+12x-1

Answer 1

Hi Charles T.,

Set y = 0 and use the quadratic formula, x = [-b ± √(b² - 4ac)] / (2a) with a = -2, b = 12 and c = -1, to find the x-intercepts.

x = [-12 ± √(12² - 4(-2)(-1))] / 2(-2)

x = [-12 ± √(136)] / -4

x = [-12 ± 2√(34)] / -4

x = [-12 + 2√(34)] / -4 and x = [-12 - 2√(34)] / -4

x = [6 - √(34)] /2 and x = [6 + √(34)] / 2

I hope this helps, Joe.