Find the value of k such that the quadratic equation x² + kx + 16 = 0 has real and distinct roots.
Show answer & explanation
Correct answer: A
Explanation
Quadratic equation: x² + kx + 16 = 0
D = b² − 4ac
For real and distinct roots, D > 0
Here, a = 1, b = k, c = 16
D = k² − 4(1)(16)
D = k² − 64
k² − 64 > 0
k² > 64
k > 8 or k < −8
k > 8