Question

Write the cofficinent of x2 in (x2-1)(x-1)

Answer 1

$(x^{2}-1)(x-1) \\= x^{2}(x-1)-1(x-1)\\= x^{3}-x^{2}-x+1\\= x^{3}-x^{2}-x+1$

$Now, Coefficient \:of \:x^{2} \:in \:(x^{2}-1)(x-1)\\= Coefficient \:of \:x^{2}\:in \: x^{3}-x^{2}-x+1 \\= -1$

Therefore.,

$\red {Coefficient \:of \:x^{2} \:in \:(x^{2}-1)(x-1)}\green {= -1}$

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