17. if $y(0)= - 2$, what is the particular solution for $\frac{dy}{dx}=\frac{6x^{2}}{y}$?\n a. $y =…

17. if $y(0)= - 2$, what is the particular solution for $\frac{dy}{dx}=\frac{6x^{2}}{y}$?\n a. $y = sqrt{4x^{3}+2}$ b. $y=sqrt{4x^{3}+4}$ c. $y=-2sqrt{x^{3}+1}$ d. $y =-sqrt{4x^{3}+2}$
Answer
Explanation:
Step1: Separate variables
We start with $\frac{dy}{dx}=\frac{6x^{2}}{y}$. Cross - multiply to get $y;dy = 6x^{2};dx$.
Step2: Integrate both sides
Integrate $\int y;dy=\int6x^{2};dx$. Using the power rule $\int x^{n}dx=\frac{x^{n + 1}}{n+1}+C$ ($n\neq - 1$), we have $\frac{y^{2}}{2}=6\times\frac{x^{3}}{3}+C$, which simplifies to $\frac{y^{2}}{2}=2x^{3}+C$.
Step3: Use the initial condition
Given $y(0)=-2$. Substitute $x = 0$ and $y=-2$ into $\frac{y^{2}}{2}=2x^{3}+C$. Then $\frac{(-2)^{2}}{2}=2\times0^{3}+C$, so $C = 2$.
Step4: Solve for y
We have $\frac{y^{2}}{2}=2x^{3}+2$, then $y^{2}=4x^{3}+4$. Since $y(0)=-2$, $y=-\sqrt{4x^{3}+4}$.
Answer:
d. $y =-\sqrt{4x^{3}+2}$ (There is a small error in the original problem - the correct general form after solving should be $y =-\sqrt{4x^{3}+4}$, but among the given options, the closest one in form is d. with a possible mis - typing in the constant term in the options)