1.

`int_(1//pi)^(2//pi)(sin(1//x))/(x^(2))dx=?`A. `1`B. `(1)/(2)`C. `(3)/(2)`D. none of these

Answer» Put `(1)/(x)=t` and `(1)/(x^(2))dx=-dt`.
`[x=(1)/(pi)impliest=pi]` and `[x=(2)/(pi)impliest=(pi)/(2)]`
`:. I=-int_(pi)^(pi//2)sintdt=int_(pi//2)^(pi)sintdt=[-cost]_(pi//2)^(pi)=1`.


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