Question

Term independent of x in $(x-\frac{1}{x}{)}^4(x+\frac{1}{x}{)}^3$ is

• A. 1
• B. 2
• C. 0
• D. 4

Answer 1

Answer: (C)

0

$={(x-\frac{1}{x})}^4{(x+\frac{1}{x})}^3$

$={(x-\frac{1}{x})}^3(x^2-\frac{1}{x^2})$$\text{If we expand it, then}$

$=x^7-x^5-\frac{1}{x^5}+\frac{1}{x^7}-3x^3+3x+\frac{3}{x}-\frac{3}{x^3}$

$\text{No term is independent of}x$

$\therefore \text{Ans =}0$

$\text{option (}c\text{)}$