1.

the derivative of `y=(1-x)(2-x)..........(n-x)` at `x=1` is equal toA. `0`B. `(-1)(n-1)!`C. `n!-1`D. `(-1)^(n-1)(n-1)!`

Answer» Correct Answer - B
`(dy)/(dx)=[(2-x)(3-x)…(n-x)+(1-x)(3-x)…….`
`(n-x)……_(1-x)(2-x)…..(n-1-x)]`
At `x=1, (dy)/(dx)=-[(n-1)!+0+0+…….+0]`
`(dy)/(dx)=(-1)(n-1)!`


Discussion

No Comment Found

Related InterviewSolutions