Given that q(x) = 6x^3+7x^2-21x+8 and q(1) = 0, find the remaining zeros of q(x)

Answer 1

use long division or synthetic division to divide q(x) by (x-1) to get

6x^2 +13x +8. Factor or use the quadratic formula to get the other two zeroes

It sort of looks factorable, as 8x2-3x1 = 13, but the signs are wrong

so use the formula

x= -13/12 + or - (1/12)sqr(169-192) = -13/12+ or - isqr23/12

the other 2 zeroes are complex numbers