解答
∫3x2(x3+4)10dx
解答
11x33+4x30+80x27+960x24+7680x21+43008x18+172032x15+491520x12+983040x9+1310720x6+1048576x3+C
求解步骤
∫3x2(x3+4)10dx
提出常数: ∫a⋅f(x)dx=a⋅∫f(x)dx=3⋅∫x2(x3+4)10dx
乘开 x2(x3+4)10:x32+40x29+720x26+7680x23+53760x20+258048x17+860160x14+1966080x11+2949120x8+2621440x5+1048576x2
=3⋅∫x32+40x29+720x26+7680x23+53760x20+258048x17+860160x14+1966080x11+2949120x8+2621440x5+1048576x2dx
使用积分加法定则: ∫f(x)±g(x)dx=∫f(x)dx±∫g(x)dx=3(∫x32dx+∫40x29dx+∫720x26dx+∫7680x23dx+∫53760x20dx+∫258048x17dx+∫860160x14dx+∫1966080x11dx+∫2949120x8dx+∫2621440x5dx+∫1048576x2dx)
∫x32dx=33x33
∫40x29dx=34x30
∫720x26dx=380x27
∫7680x23dx=320x24
∫53760x20dx=2560x21
∫258048x17dx=14336x18
∫860160x14dx=57344x15
∫1966080x11dx=163840x12
∫2949120x8dx=327680x9
∫2621440x5dx=31310720x6
∫1048576x2dx=31048576x3
=3(33x33+34x30+380x27+320x24+2560x21+14336x18+57344x15+163840x12+327680x9+31310720x6+31048576x3)
化简 3(33x33+34x30+380x27+320x24+2560x21+14336x18+57344x15+163840x12+327680x9+31310720x6+31048576x3):11x33+4x30+80x27+960x24+7680x21+43008x18+172032x15+491520x12+983040x9+1310720x6+1048576x3
=11x33+4x30+80x27+960x24+7680x21+43008x18+172032x15+491520x12+983040x9+1310720x6+1048576x3
解答补常数=11x33+4x30+80x27+960x24+7680x21+43008x18+172032x15+491520x12+983040x9+1310720x6+1048576x3+C