Expert: Ahmed Salami - 1/14/2009

Question
Im having a severe getting this problem correct none of my answers match the answers given.
Solve the equation and express each solution in a+bi form.
4x^2-8x^2-48=0
if you could help me out that would be great I tried asking other people but no luck.
Thanks!!

Answer
Hi Aisha,
I'm guessing you meant to write 4x^2 - 8x - 48 = 0 and not 4x^2 - 8x^2 - 48 = 0 !!!
Ok then,
4x^2 - 8x - 48 = 0
divide through by 4
x^2 - 2x - 12 = 0
And this equation clearly doesnt have complex roots of the form a+bi
You can always check for this in any ax^2 + bx + c = 0 by considering the value of b^2 - 4ac
b^2 - 4ac > 0   real distinct roots
b^2 - 4ac = 0   double roots
b^2 - 4ac < 0   complex conjugate roots p(+-)qi

Regards