xiaoyu_05
幼苗
共回答了27个问题采纳率:88.9% 举报
(a)(dy/dx)+2y=12 → [d(y-6)/dx]=-2(y-6) → [d(y-6)]/(y-6)=-2dx → ln|y-6|=-2x+C;
∵ y(0)=1,ie:ln|1-6|=2*0+C,thus C=ln5 ;
therefore the solution is y=6-e^(ln5-2x)=1-e^(-2x);
(b)(dy/dx)=y-2 → [d(y-2)]/(y-2)=dx → ln|y-2|=x+C ;
∵ y(1)=1,ie:ln|1-2|=1+C,thus C=-1;
therefore the solution is y=2-e^(x-1);
1年前
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