Question 1038234
How would I solve y=4x^2-16x-5 by "completing the square?"
-------------
y=4x^2-16x-5 = 0
4x^2-16x = 5
x^2-4x = 5/4
Add c.  c = (b/2a)^2 = (-4/2)^2 = 4
Add to both sides
x^2-4x+4 = 5/4 + 4 = 21/4
(x-2)^2 = 21/4
x-2 = ħsqrt(21/4) = ħsqrt(21)/2
{{{x = 2 +-sqrt(21)/2}}}