• Nov 15th 2008, 04:48 PM
xwrathbringerx
Hi

Find the values of k for which the equation x^2 + 16x - 4k = 0 has the roots differing by 6.

I tried doing: Let the roots be a and a - 6 but that obviously doesn't get me any close to the answer. (Crying)

Thanx
• Nov 15th 2008, 05:04 PM
mr fantastic
Quote:

Originally Posted by xwrathbringerx
Hi

Find the values of k for which the equation x^2 + 16x - 4k = 0 has the roots differing by 6.

I tried doing: Let the roots be a and a - 6 but that obviously doesn't get me any close to the answer. (Crying)

$x = 8 + 2 \sqrt{16+k}$ and $x = 8 - 2 \sqrt{16+k}$.
Take the difference: $4 \sqrt{16 + k}$.