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Question

Question: Coefficient of x in f(x)= \(\left| \begin{matrix} x & (1 + \sin x)^{3} & \cos x \\ 1 & \log(1 + x) &...

Coefficient of x in f(x)= x(1+sinx)3cosx1log(1+x)2x2(1+x)20\left| \begin{matrix} x & (1 + \sin x)^{3} & \cos x \\ 1 & \log(1 + x) & 2 \\ x^{2} & (1 + x)^{2} & 0 \end{matrix} \right| is –

A

0

B

1

C

– 2

D

Cannot be determined

Answer

– 2

Explanation

Solution

Coefficient of x in

x(1+xx33!)31x22!....1xx22+...2x21+x20\left| \begin{matrix} x & \left( 1 + x - \frac{x^{3}}{3!} \right)^{3} & 1 - \frac{x^{2}}{2!}.... \\ 1 & x - \frac{x^{2}}{2} + ... & 2 \\ x^{2} & 1 + x^{2} & 0 \end{matrix} \right| Coefficient of x in

x & 1 & 1 \\ 1 & x & 2 \\ x^{2} & 1 & 0 \end{matrix} \right|$$ Coefficient of x in [x (0 – 2) – 1 (0 – 2x<sup>2</sup>) + 1 (1 – x<sup>2</sup>)] = – 2