y=Ce^(-S2/xdx) e^(-S2/xdx)Sx^3e^(S2/xdx)dx=多少
数学
y=Ce^(-S2/xdx) e^(-S2/xdx)Sx^3e^(S2/xdx)dx
=Ce^(-ln(x^2)) e^(-ln(x^2))Sx^3e^(ln(x^2)dx
=C/x^2 1/x^2*Sx^5dx
=C/x^2 1/6*x^6/x^2
=C/x^2 x^4/6
问:若7x-2y=0,则[(x/y)-(y/x)]/[(x/y)-1 (y/x)]=?
答:7x-2y=0, 即x/y=2/7 y/x=7/2 [(x/y)-(y/x)]/[(x/y)-1+(y/x)] =[(2/7)-(7/2)]/[(2/7)-1+...详情>>
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