Question

Find the values of k for which the roots of 9x²+8kx+16=0 real and equal​

Answer 1

Step-by-step explanation:

$a = 9 \: b = 8k \: c = 16 \\ discriminent \: = 0 \\ \sqrt{ {b}^{2} - 4ac} = 0 \\ {(8k)}^{2} - 4 \times 9 \times 16 = 0 \\ 64 {k}^{2} - 576 = 0 \\ 64 {k}^{2} = 576 \\ {k}^{2} = \frac{576}{64} \\ {k}^{2} = 9 \\ k = 3$