1.

If `lim_(x->oo)((1+a^3)+8e^(1/ x))/(1+(1-b^3)e^(1/ x))=2,` then there existsA. `a=1,b=(-3)^(1//3)`B. `a=1,b=3^(1//3)`C. `a=-1,b=-(3)^(1//3)`D. none of these

Answer» Correct Answer - A
We have,
`lim_(xto0)((1+a^3)+8e^(1//x))/(1+(1-b^3)e^(1//x))=2 [(oo)/(oo)"form"]`
`rArr lim_(xto0) ((1+a^3)e^(-1//x)+8)/(e^(-1//x)+(1-b^3))=2`
`rArr (0+8)/(0+(-b^3))=2 rArr 1-b^3=4rArr b^3=-3rArr b=(-3)^(1//3)`
Again,
`lim_(xto0) ((1+a^3)+8e^(1//x))/(1+(1-b^3)e^(1//x))=2`
`rArrlim_(xto0) ((1+a^3)+8e^(1//x))/(1+4e^(1//x))=2`
`rArr 1+a^3=2`
` rArr a=1`


Discussion

No Comment Found