The value of $$\int_a^b {{{{x^7} + \sin x} \over {\cos x}}} dx$$, where a + b = 0, is

If 0 < a < b, then $$\int_a^b {{{|x|} \over x}} dx$$ is equal to

$$\int_0^{2\pi } {{{\sin }^5}\left( {{x \over 4}} \right)dx} $$ is equal to

$$\int_{ - 1}^1 {x|x|} \,dx$$ is equal to