Separation of Variables

AP Calculus AB· difficulty 4/5

Solve dydx=xy\dfrac{dy}{dx} = xy with y(0)=2y(0) = 2. Then y(1)=y(1) =

  • A

    2e2\sqrt{e}

    check_circle
  • B

    e1/2e^{1/2}

  • C

    2e2e

  • D

    2e\sqrt{2e}

Explanation

Separate: dy/y=xdxlny=x2/2+Cdy/y = x\,dx \Rightarrow \ln|y| = x^2/2 + C. y(0)=2y(0)=2: ln2=C\ln 2 = C. So y=2ex2/2y = 2 e^{x^2/2}. y(1)=2e1/2=2ey(1) = 2e^{1/2} = 2\sqrt{e}.

Want 10 more like this — adaptive to your weak spots?

Related questions