4-x^2=4-2x
x^2-2x=0
x*(x-2)=0
[b]x=0[/b] или x-2=0 ⇒ [b]x=2[/b]
По правилу ( см. скрин 2)
[m]S= ∫ ^{2}_{0}( \underbrace{(4-x^2)}_{f_{2}(x)}-\underbrace{(4-2x)}_{f_{1}(x)})dx=∫ ^{2}_{0}(4-x^2-4+2x)dx=∫ ^{2}_{0}(2x-x^2)dx=[/m]
[m]=(x^2-\frac{x^3}{3})|^{2}_{0}=(2^2-\frac{2^3}{3})-(0^2-\frac{0^3}{3})=\frac{4}{3}[/m]