Originally Posted by

**Lexielai** Alright, so I've tried 1/2ab=8^2 and solved for b, getting b = 128/a. Then I tried plugging that into the equation a^2 + b^2 = 64, like so:

**a^2 + (128/a)^2 = 64**

a^ 2 + (16384/a^2) = 64

16384/a^2 = 64 - a^2

16384 = 64a^2 -a^4

-a^4 + 64a^2 - 16384 = 0

-1(a^4 - 64a^2 + 16384) = 0

a^4 - 64a^2 + 16384 = 0

Then, when I tried to solve for that with the quadratic formula:

-(-64) +/- sqrt[(-64)^2 - 4(1)(16384)]/2(1)

I got an imaginary answer, since 4096 - 65536 = a negative number, which you can't find a real square root of.

I'm still stuck, so can someone shed some light on what I did wrong?