Q5 of 47 Page 1

Find the value of k for which the roots of the quadratic equation 2x2 + kx + 8 = 0 will have equal value.

The given equation is of the form ax2 + bx + c = 0

The discriminant D = b2 - 4ac


If the quadratic equation has equal root then its discriminant D = 0


According to the problem:


D = k2-(4 × 2 × 8) = 0


⇒ k2 = 64


Answer: The value of k = 8,-8


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