Q5 of 108 Page 46

If the roots of the quadratic equation x2 – kx + 4 = 0 are equal then the value of k will be:

x2 – kx + 4 = 0

When we compare the above quadratic equation with the generalized one we get,


ax2 + bx + c = 0


a = 1


b = -k


c = 4


Since the quadratic equations have real and equal roots,


b2 – 4ac = 0 for real and equal roots


⟹ (-k) 2 – (4 × 1 × 4) = 0


⟹ k2 – 16 = 0


⟹ k2 = 16


⟹ k= ± 4


So the correct answer is C [4].

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