MCQ
$\lambda $ ની કઈ કિમત માટે ${x^2}{\left( {\sqrt x + \frac{\lambda }{{{x^2}}}} \right)^{10}}$ ના વિસ્તરણમાં $x^2$ સહગુણક $720$ થાય ?
- ✓$4$
- B$2\sqrt 2 $
- C$\sqrt 5 $
- D$3$
Consider constant term
$^{10} \mathrm{C}_{\mathrm{r}}(\sqrt{\mathrm{x}})^{10-\mathrm{r}}\left(\frac{\lambda}{\mathrm{x}^{2}}\right)^{r}$
$\frac{10-r}{2}-2 r=0$
$10-5 r=0$
$r=2$
$\Rightarrow^{10} \mathrm{C}_{2} \times \lambda^{2}=720$
$ \Rightarrow \lambda=4$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
| વર્ગ: | $0-10$ | $10-20$ | $20-30$ | $30-40$ | $40-50$ |
| આવૃતિ | $2$ | $3$ | $x$ | $5$ | $4$ |
નો મધ્યક $28$ હોય,તો તેનું વિચરણ $.........$ છે.