Q3 of 108 Page 46

If one zero of the polynomial 2x2 + x + k is 3 then the value of k will be:

Given one zero = 3

Let second zero a.


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


ax2 + bx + c = 0


∴ a = 2, b = 1, c = k


Sum of zeroes = -b/a


3 + a = -1/2


a = -1/2 – 3


a = -7/2


Product of zeroes = 3 × (-7/2)


= -21/2


Product of zeroes = c/a


k/2 = -21/2


k = -21


So the correct answer is D [-21].

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