dy/dx =2y+1
∫dy/(2y+1) =∫ dx
(1/2)ln|2y+1| = x+C'
ln|2y+1| = 2x+2C'
2y+1 =Ce^(2x)
y= [-1+Ce^(2x)]/2
y(0) =3
3= [-1+C]/2
C=7
ie
y= [-1+7e^(2x)]/2
解:微分方程为dy/dx=2y+1,化为y'-2y=1,y'e⁻²ˣ-2e⁻²ˣy=e⁻²ˣ,(ye⁻²ˣ)'=e⁻²ˣ,ye⁻²ˣ=-0.5e⁻²ˣ+c(c为任意常数),微分方程的通解为y=ce²ˣ-0.5
∵y(0)=3 ∴有3=c-0.5,得:c=3.5
微分方程的特解为y=3.5e²ˣ-0.
解微分方程
请参考