1.

The integral `int_(0)^(pi)sqrt(1+4"sin"^(2)x/2-4"sin"x/2)dx` equalsA. `pi-4`B. `(2pi)/3-4-sqrt(3)`C. `4sqrt(3)-4`D. `4sqrt(3)-4-(pi)/3`

Answer» Correct Answer - D
`I=int_(0)^(pi)sqrt(1+4"sin"^(2)x/2-4"sin"x/2)dx`
`=int_(0)^(x)|1-2"sin"x/2|dx`
`=int_(0)^(pi//3)|1-2"sin"x/2|dx`
`=int_(0)^(pi//3) (1-2"sin"x/2)dx+int_(pi//3)^(pi)(2"sin"x/2-1)dx`
`=(x+4"cos"x/2)|._(0)^(pi//3)+(-4"cos"x/2-x)|_(pi//3)^(pi)`
`=4sqrt(3)-4-(pi)/3`


Discussion

No Comment Found