Q3 of 64 Page 49

Find the zeros, the sum and the product of zeros of p(x) = 4x2 + 12x + 5.

Given, p(x) = 4x2 + 12x + 5


= 4x2 + 10x + 2x + 5


= 2x(2x + 5) + 1(2x + 5)


= (2x + 5)(2x + 1)


To find the zeros of p(x), put p(x) = 0


∴ (2x + 5)(2x + 1) = 0


∴ x = – or x = –


The zeros of p(x) are – and – .


Now, sum of zeros = = = –3


and, product of zeros = – × – =


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