How do you find the zeros, real and imaginary, of y=5(x-3)^2-56 using the quadratic formula?

1 Answer
Jan 10, 2016

x = 3 +- 3,35

Explanation:

Develop y = 5(x^2 - 6x + 9) - 56 = 5x^2 - 30x + 45 - 56
y = 5x^2 - 30x - 11 = 0
D = d^2 = b^2 - 4ac = 900 + 220 = 1120 --> d = +- 33.47.
There are 2 real roots:
x = 30/10 +- 33.47/10 = 3 +- 3.35
x1 = 6.35 and x2 = 0.35