y = −∜x; x = 81; x = 256 и осью абсцисс.
g(x)=-\sqrt[4]{x}
S= ∫ _{81}^{256}(0-(-\sqrt[4]{x}))dx=∫ _{81}^{256}\sqrt[4]{x}dx=\frac{x^{\frac{1}{4}+1}}{\frac{1}{4}+1} _{81}^{256}=\frac{4}{5}(256^{\frac{5}{4}}-81^{\frac{5}{4}})=\frac{4}{5}\cdot (4^5-3^5)=\frac{4}{5}\cdot (1024-243)=\frac{3124}{5}=624,8