3道高数题作业希望和大家对对答案
(1)本题选D
dy/dx
=d[1+x-e^(-x)]/dx
=0+1+e^x
=1+e^x
(2)本题选B
∫(2x-3x^2)dx(0→1)
=(x^2-x^3)|(0→1)
=1-1-(0-0)
=0
(3)本题选A,第(1)步开始出错
令t=x^2
∫xsin(x^2)dx(0→1)
=(1/2)∫sin(x^2)d(x^2)(0→1)
=(1/2)∫sintdt(0→1)
=(1/2)(-cost)|(0→1)
=(1/2)(1-cos1)。
(1)本题选D
dy/dx
=d[1+x-e^(-x)]/dx
=0+1+e^x
=1+e^x
(2)本题选B
∫(2x-3x^2)dx(0→1)
=(x^2-x^3)|(0→1)
=1-1-(0-0)
=0
(3)本题选A,第(1)步开始出错
令t=x^2
∫xsin(x^2)dx(0→1)
=(1/2)∫sin(x^2)d(x^2)(0→1)
=(1/2)∫sintdt(0→1)
=(1/2)(-cost)|(0→1)
=(1/2)(1-cos1)。
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