Question 549818
f(x) = x^4-16



0 = x^4-16



x^4-16 = 0



(x^2-4)(x^2+4) = 0



(x-2)(x+2)(x^2+4) = 0



x-2=0, x+2=0, or x^2+4=0



x=2, x=-2, x=2i, or x=-2i



So the real roots are 2 and -2