Find the term independent of x (x 0, x neq | vedclass

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Question

(B) Simplify the expression inside the bracket: $\left[\frac{(x^{1/3})^3+1^3}{x^{2/3}-x^{1/3}+1} - \frac{(\sqrt{x}-1)(\sqrt{x}+1)}{\sqrt{x}(\sqrt{x}-1

Vedclass · Accepted Answer

$210$

Vedclass · Answer

(B) Simplify the expression inside the bracket: $\left[\frac{(x^{1/3})^3+1^3}{x^{2/3}-x^{1/3}+1} - \frac{(\sqrt{x}-1)(\sqrt{x}+1)}{\sqrt{x}(\sqrt{x}-1)}ight]^{10}$ $= \left[(x^{1/3}+1) - \frac{\sqrt{x}+1}{\sqrt{x}}ight]^{10} = \left[x^{1/3}+1 - (1+x^{-1/2})ight]^{10} = (x^{1/3}-x^{-1/2})^{10}$. The general term $T_{r+1}$ is given by: ${}^{10}C_r (x^{1/3})^{10-r} (-x^{-1/2})^r = {}^{10}C_r (-1)^r x^{\frac{10-r}{3} - \frac{r}{2}}$. For the term independent of $x$,the exponent of $x$ must be $0$: $\frac{10-r}{3} - \frac{r}{2} = 0$. $20 - 2r - 3r = 0$ $\Rightarrow 5r = 20$ $\Rightarrow r = 4$. The term is ${}^{10}C_4 (-1)^4 = \frac{10 	imes 9 	imes 8 	imes 7}{4 	imes 3 	imes 2 	imes 1} = 210$.

Find the term independent of $x$ $(x > 0, x \neq 1)$ in the expansion of $\left[\frac{(x+1)}{\left(x^{2/3}-x^{1/3}+1\right)}-\frac{(x-1)}{(x-\sqrt{x})}\right]^{10}$.

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