1.

`int_(-pi)^(pi)x^(3)cos^(3)xdx=?`A. `pi`B. `(pi)/(4)`C. `2pi`D. `0`

Answer» `f(x)=x^(3)cos^(3)x`.
`:.f(-x)=(-x)^(3)[cos(-x)]^(3)=-x^(3)(cosx)^(3)=-(x^(3)cos^(3)x)=-f(x)`
`:.f(x)` is odd and hence `I=0`.


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