How do you find the roots, real and imaginary, of #y=7x^2-2x + 6# using the quadratic formula?

1 Answer
Apr 11, 2016

Answer:

# (1 +- 6.4i)/7#

Explanation:

#y = 7x^2 - 2x + 6 = 0#
Use the improved quadratic formula, also called the quadratic formula in intercept form (Google, Yahoo, Bing Search).
#D = d^2 = b^2 - 4ac = 4 - 168 = -164# --> #d = +- 12.80( i )#
Since D < 0, there are no real roots. There are 2 complex roots -->
#x = -b/(2a) +- d/(2a) = 2/14 +- (12.80i)/14 = (1 +- 6.4i)/7#