The particular solution of the differential equation $(y-x^2y)dy = (1-x^3)dx$ with $y(0) = 1$, is: |
$y^2 = x^2+2 \log_e|1+x|+1$ $y^2=1+x^2+2 \log_e\left|\frac{1+x}{2}\right|$ $y^2=x^2+2x-3$ $y^2 = x^2+2x+1$ |
$y^2 = x^2+2 \log_e|1+x|+1$ |
The correct answer is Option (1) → $y^2 = x^2+2 \log_e|1+x|+1$ $(y-x^2y)dy=(1-x^3)dx$ $⇒y(1-x^2)dy=(1-x^3)dx$ $⇒ydy=\frac{1-x^3}{1-x^2}dx$ $⇒\int ydy=\int\frac{(1-x)(1+x^2+x)}{(1-x)(1+x)}dx$ $⇒\frac{y^2}{2}=\int\frac{x(1+x)+1}{(1+x)}dx$ $⇒\frac{y^2}{2}=\frac{x^2}{2}+\int\frac{1}{1+x}dx$ $⇒y=x^2+2\log|x+1|+2C$ and, $y(0)=1$ $⇒1=0+0+2C$ $⇒C=\frac{1}{2}$ $∴y=x^2+2\log|x+1|+1$ |