InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
Find the value of n, if `lim_(xto2) (x^(n)-2^(n))/(x-2)=80`, `n in N`.A. `3`B. `5`C. `4`D. `6` |
|
Answer» Correct Answer - B Given, `underset(xto2)"lim"(x^(n)-2^(n))/(x-2)=80` `rArr n(2)^(n-1)=80` `[therefore underset(xtoa)"lim"(x^(n)-a^(n))/(x-a)=na^(n-1)]` `rArr n(2)^(n-1)= 5 xx 16` `rArr n xx 2^(n-1)= 5 xx (2)^(4)` `rArr n xx 2^(n-1)= 5 xx (2)^(5-1)` `therefore n=5` |
|