∫02(2x2−3x+[x−21])dx
=∫022x2−3xdx+∫02[x−21]dx
Let I1=∫022x2−3xdx=∫023(3x−2x2)dx+∫232(2x2−3x)dx
=(23x2−32x3)023+(32x3−23x2)232
=(827−49)+(38−6−49+827)=49−310=1219
Let I2=∫02[x−21]dx
Assume x−21=t
i.e. I2=∫2−123[t]dt
=∫−210(−1)dt+∫010⋅dt+∫1231⋅dt
=(−t)−210+(t)123=−21+(23−1)=0
Hence, ∫02(2x2−3x+[x−21])dx=1219