# If the equation 9x2 + 6kx + 4 = 0 has equal roots then k = ?A. 2 or 0B. - 2 or 0C. 2 or - 2D. 0 only

The equation 9x2 + 6kx + 4 = 0 has equal roots

a = 9 b = 6k c = 4

Then D = b2 - 4ac = 0

(6k)2 - 4.9.4 = 0

36k2 = 144

k2 = 4 taking square root both sides

k = 2 or k = - 2

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