2.∫(от 0 до π) sin x/4 dx
=(1/3)-4*(1/2)+4 - (-8/3)+4*(4/2)-4*(-2)=
=3-2+4+8+8=21
или
∫^(1)_(-2)(x^2–4x+4) dx= ∫^(1)_(-2)(x-2)^2 d(x-2)=((x-2)^3/3)|^(1)_(-2)=
=(-1/3)-(-4)^3/3=63/3=21
2.∫^(π)_(0) sin (x/4) dx=4* ∫^(π)_(0) sin (x/4) d(x/4)=
=4*(- cos(x/4))|^(π)_(0)= 4*(-cos(π/4)+cos0)= 4*((-sqrt(2)/2) + 1)=
=-2sqrt(2) + 4