For what value of k is 4x\(^2\) – 12x + k, a perfect square?
- -9
- \(\frac{-9}{4}\)
- \(\frac{9}{4}\)
-
9
The correct answer is: D
Explanation
4x\(^2\) - 12x + k;
a = 4, b = -12, c = k.
For perfect square b\(^2\) = 4ac
(-12)\(^2\) = 4 * 4 * k;
144 = 16k
k = 144\16
k = 9