自我小测1.下列等式不正确的是()A.1112013xdx=0B.112014dx=4028C.112014x3dx=0D.11cosxdx=02.若e为自然对数的底数,则32e2-xdx=()A.1e-1B.1-1eC.1-eD.e-13.53x2+1xdx等于()A.8-ln53B.8+ln53C.16-ln53D.16+ln534.0k(2x-3x2)dx=0,则k等于()A.1B.0C.0或1D.不确定5.下列定积分不大于0的是()A.11|x|dxB.11(1-|x|)dxC.11|x-1|dxD.11(|x|-1)dx6.计算:211x+1x2dx=__________.7.设函数f(x)=ax2+c(a≠0),若10f(x)dx=f(x0),0≤x0≤1,则x0的值为__________.8.若f(x)=-ex,x1,|x|,x≤1,则20f(x)dx=__________.9.计算定积分:(1)17π3π3(2sinx-3cosx)dx;(2)aax2dx(a>0);(3)211x(x+1)dx.10.设f(x)是一次函数,且10f(x)dx=5,10xf(x)dx=176,求f(x)的解析式.参考答案1.解析:112013xdx=2013x2211|=20132-20132=0,112014dx=2014x11|=4028,112014x3dx=20144x411|=0,11cosxdx=sinx11|=sin1-sin(-1)=2sin1.故D不正确.答案:D2.解析:32e2-xdx=-e2-x32|=-e-1+e0=1-1e.答案:B3.解析:53x2+1xdx=53xdx+531xdx=12x253|+lnx53|=12(52-32)+ln5-ln3=8+ln53,故选B.答案:B4.解析:∵0k(2x-3x2)dx=(x2-x3)0|k=k2-k3,∴k2-k3=0,即k=0或k=1.又∵k=0时不合题意,∴k=1.答案:A5.解析:11|x|dx=01(-x)dx+10xdx=-12x201|+12x201|=1,11(1-|x|)dx=01(1+x)dx+10(1-x)dx=1,11|x-1|dx=11(1-x)dx=2,11(|x|-1)dx=11(1-|x|)dx=-1.答案:D6.解析:211x+1x2dx=lnx-1x21|=ln2-12-(ln1-1)=ln2+12.答案:ln2+127.解析:10f(x)dx=10(ax2+c)dx=13ax3+cx10|=a3+c=ax20+c,∵0≤x0≤1,∴x0=33.答案:338.解析:20f(x)dx=10|x|dx+21(-ex)dx=10xdx+21(-ex)dx=12x210|+(-ex)21|=12-e2+e.答案:12-e2+e9.解:(1)17π3π3(2sinx-3cosx)dx=217π3π3sinxdx-317π3π3cosxdx=2(-cosx)17π3π3|-3sinx17π3π3|=2-cos17π3+cosπ3-3sin17π3-sinπ3=2-12+12-3-32-32=33.(2)由x2=x,x≥0,-x,x0,得aax2dx=0axdx+0a(-x)dx=12x20|a-12x20|a=a2.(3)f(x)=1x(x+1)=1x-1x+1,取F(x)=lnx-ln(x+1)=lnxx+1,则F′(x)=1x-1x+1.所以211x(x+1)dx=211x-1x+1dx=lnxx+121|=ln43.10.解:设f(x)=ax+b(a≠0),则10f(x)dx=10(ax+b)dx=10axdx+10bdx=12a+b=5,10xf(x)dx=10x(ax+b)dx=10ax2dx+10bxdx=13a+12b=176.由12a+b=5,13a+12b=176,解得a=4,b=3.故f(x)=4x+3.