Question

The roots of the equation are 3 + 8i and 3 – 8i.

Answer 1

Given that the roots of the equation x^2-6x+c=0 are 3+8i and 3-8i, the value of c can be obtained as follows;
taking x=3+8i and substituting it in our equation we get:
(3+8i)^2-6(3+8i)+c=0
-55+48i-18-48i+c=0
collecting the like terms we get:
-55-18+48i-48i+c=0
-73+c=0
c=73
the answer is c=73