Tính :
a) \(\int\limits^{\dfrac{\pi}{2}}_0\cos2x.\sin^2dx\)
b) \(\int\limits^1_{-1}\left|2^x-2^{-x}\right|dx\)
c) \(\int\limits^2_1\dfrac{\left(x+1\right)\left(x+2\right)\left(x+3\right)}{x^2}dx\)
d) \(\int\limits^2_0\dfrac{1}{x^2-2x-3}dx\)
e) \(\int\limits^{\dfrac{\pi}{2}}_0\left(\sin x+\cos x\right)^2dx\)
g) \(\int\limits^{\pi}_0\left(x+\sin x\right)^2dx\)