Can the quadratic polynomial x2 + kx + k have equal zeroes for some odd integer k > 1?


No, the quadratic polynomial x2 + kx + k cannot have equal zeroes for some odd integer k > 1

Let suppose, if it has equal zeroes


the zeroes of a quadratic polynomial are equal when discriminate is equal to 0


i.e., D = 0


b2 - 4ac = 0


b2 = 4ac


k2 = 4k


k = 0 or k = 4


But it is given that k > 1, so we reject the value k = 0 < 1


k = 4


But 4 is not an odd number and only at k = 4 will the polynomial get equal roots.


Hence, the quadratic polynomial x2 + kx + k cannot have equal zeroes for some odd integer k > 1


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