Question

`lim_(x->oo)((x+c)/(x-c))^x= 4` then find c.
A. `log_(10)2`
B. `log_e 2`
C. `2`
D. none of these

Answer 1

Correct Answer - B
`lim_(xto oo) ((x+c)/(x-c^x))^x=4`
` rArr lim_(x to oo) (1+(2c)/(x-c))^x=4`
`rArr e^(lim_(xto oo)(2cx)/(x-c))=4rArr e^(2c)=2rArr c=log_e 2` .