Asked by Joshua
The roots of the quadratic equation z^2 + az + b = 0 are 2 - 3i and 2 + 3i. What is a+b?
Can you please help me with this question?
Can you please help me with this question?
Answers
Answered by
Steve
well, the equations is
(x-(2-3i))(x-(2+3i)) = 0
((x-2)+3i)((x-2)-3i) = 0
(x-2)^2 + 3^2 = 0
x^2-4x+4 + 9 = 0
x^2-4x+13 = 0
a+b = -4+13 = 9
(x-(2-3i))(x-(2+3i)) = 0
((x-2)+3i)((x-2)-3i) = 0
(x-2)^2 + 3^2 = 0
x^2-4x+4 + 9 = 0
x^2-4x+13 = 0
a+b = -4+13 = 9