If x2 + kx + \(\frac{16}{9}\) is a perfect square, find the value of k
A
\(\frac{8}{3}\)
B
\(\frac{7}{3}\)
C
\(\frac{5}{3}\)
D
\(\frac{2}{3}\)
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
x2 + kx + \(\frac{16}{9}\); Perfect square
But, b2 - 4ac = 0, for a perfect square
where a - 1; b = k; c = \(\frac{16}{9}\)
k2 - 4(1) x \(\frac{16}{9}\) = 0
k2 - \(\frac{64}{9}\) = 0
k2 = \(\frac{64}{9}\)
k = \(\sqrt{\frac{64}{9}}\)
k = \(\frac{8}{3}\)
Source: Myschool Past Questions Archive (Record #36591)