∫ 0 π si n 2 (x) ⅆ x = π 10 [ f(0)+f( π 10 )+f( 2 π 10 )+f( 3 π 10 )+f( 4 π 10 )+f( 5 π 10 )+f( 6 π 10 )+f( 7 π 10 )+f( 8 π 10 )+f( 9 π 10 ) ]= = π 10 [ si n 2 (0)+si n 2 ( π 10 )+si n 2 ( 2 π 10 )+si n 2 ( 3 π 10 )+si n 2 ( 4 π 10 )+si n 2 ( 5 π 10 )+si n 2 ( 6 π 10 )+si n 2 ( 7 π 10 )+si n 2 ( 8 π 10 )+si n 2 ( 9 π 10 ) ]=1.5707963268
∫ 0 π si n 2 (x) ⅆ x = π 10 [ f(0)+f( π 10 )+f( 2 π 10 )+f( 3 π 10 )+f( 4 π 10 )+f( 5 π 10 )+f( 6 π 10 )+f( 7 π 10 )+f( 8 π 10 )+f( 9 π 10 ) ]=
= π 10 [ si n 2 (0)+si n 2 ( π 10 )+si n 2 ( 2 π 10 )+si n 2 ( 3 π 10 )+si n 2 ( 4 π 10 )+si n 2 ( 5 π 10 )+si n 2 ( 6 π 10 )+si n 2 ( 7 π 10 )+si n 2 ( 8 π 10 )+si n 2 ( 9 π 10 ) ]=1.5707963268
∫ 0 π si n 2 (x) ⅆ x = π 10 [ f(0)+f( π ) 2 +f( π 10 )+f( 2 π 10 )+f( 3 π 10 )+f( 4 π 10 )+f( 5 π 10 )+f( 6 π 10 )+f( 7 π 10 )+f( 8 π 10 )+f( 9 π 10 ) ]= = π 10 [ si n 2 (0)+si n 2 ( π ) 2 +si n 2 ( π 10 )+si n 2 ( 2 π 10 )+si n 2 ( 3 π 10 )+si n 2 ( 4 π 10 )+si n 2 ( 5 π 10 )+si n 2 ( 6 π 10 )+si n 2 ( 7 π 10 )+si n 2 ( 8 π 10 )+si n 2 ( 9 π 10 ) ]=1.5707963268
∫ 0 π si n 2 (x) ⅆ x = 1 3 ⋅ π 10 { f(0)+f( π )+2 ⋅ [ f( 2 π 10 )+f( 4 π 10 )+f( 6 π 10 )+f( 8 π 10 ) ]+4 ⋅ [ f( π 10 )+f( 3 π 10 )+f( 5 π 10 )+f( 7 π 10 )+f( 9 π 10 ) ] }= = 1 3 ⋅ π 10 { si n 2 (0)+si n 2 ( π )+2 ⋅ [ si n 2 ( 2 π 10 )+si n 2 ( 4 π 10 )+si n 2 ( 6 π 10 )+si n 2 ( 8 π 10 ) ]+4 ⋅ [ si n 2 ( π 10 )+si n 2 ( 3 π 10 )+si n 2 ( 5 π 10 )+si n 2 ( 7 π 10 )+si n 2 ( 9 π 10 ) ] }=1.5707963268