Use the quadratic formula to find the zeros of the function. Round to tenths if necessary. y = 17x^2 - 21

Y = 17x^2 - 21.

Y = (-b +-sqrt(b^2 - 4ac)) / 2a,
Y = (- 0 +- sqrt(0 - (-1428)) / 34,
Y = ( - 0 +- sqrt(0 + 1428)) / 34,
Y = +- 37.789 / 34 = +-1.11.
Or Y = 1.11, and -1.11.