The number of non-real roots of the equation x^15+1=0 is ?

x^15+1 = (x+1)(x^14 -x^13 +x^12 ---) = 0

The equation x+1=0 gives a real root

and equation (x^14 -x^13 +x^12 ---) = 0 gives 14 non-real roots.

Therefore, x^15+1 = 0 gives 1 real and 14 non-real roots.

Hope this helps

Thanks