Question

Find the value of k, if x = 2 is a zero of the polynomial p(x) = x2 + ke-2.

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Answer 1

Explanation:

$p(x) = {x}^{2} + kx - 2 \\ x = 2 \\ p(2) =( 2) {}^{2} + k \times 2 - 2 \\ p(2) = 4 + 2k - 2 \\ p(2) = 2k + 2 \\ p(2) = 0 \: because \: x = 2 \\ is \: a \: zero \: of \: polynomial \\ so \: 2k + 2 = 0 \\ 2k = - 2 \\ k = - 1$