Q3 of 47 Page 74

Verify Whether the following are roots of the polynomial equations indicated against them.

x2 + 4x + 3 = 0; x = −1, 2

x2 + 4x + 3 = 0


let p(x) = x2 + 4x + 3


p(-1) = (-1)2 + 4(-1) + 3


= 1 – 4 + 3


= 4 – 4 = 0


∴ x = -1 is a root of x2 + 4x + 3 = 0


p(x) = x2 + 4x + 3 = 0


p(2) = (2)2 + 4(2) + 3


= 4 + 8 + 3


= 11 + 4 = 15 ≠ 0


∴ x = 2 is not a root of x2 + 4x + 3 = 0.


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