Question

4x² - 2(k + 1) x + (k + 4) = 0​....find the value of k if b²-4ac=0

Answer 1

[ -2 ( k + 1 )]^2 - 4 (4) ( k + 4)
4 ( K2 + 2 K + 1 ) - 16k -64
4k2 + 8k + 4 -16 k -64 = 0
4 k2 -8k -60 = 0
K 2 - 2 k -15 = 0
K2 -5k + 3 k -15= 0
( k+ 3 ) ( k-5) = 0

K = -3, 5