Skip to main contentSkip to solution

Match List-I with List-II

List-IList-II
(Parametric equations)(dydx)\left(\frac{dy}{dx}\right)
(A) x=2t,y=2tx = \frac{2}{t}, y = 2t(I) 4t24t^2
(B) x=t3,y=3t+2x = t^3, y = 3t + 2(II) 2(t+1)2(t+1)
(C) x=logt,y=2t2x = \log t, y = 2t^2(III) t2-t^2
(D) x=et,y=2tetx = e^t, y = 2te^t(IV) t2t^{-2}

Choose the correct answer from the options given below:

Solution

Correct Option: 4

When x and y are functions of parameter t, the derivative is found using:

dydx=dy/dtdx/dt\frac{dy}{dx} = \frac{dy/dt}{dx/dt}


For x=2t,y=2tx = \frac{2}{t}, y = 2t:

x=2t1x = 2t^{-1}

dxdt=2t2\frac{dx}{dt} = -2t^{-2}

=2t2= -\frac{2}{t^2}

dydt=2\frac{dy}{dt} = 2

dydx=22/t2\frac{dy}{dx} = \frac{2}{-2/t^2}

=2×(t22)= 2 \times \left(-\frac{t^2}{2}\right)

=t2= -t^2

(A) matches with (III)


For x=t3,y=3t+2x = t^3, y = 3t + 2:

dxdt=3t2\frac{dx}{dt} = 3t^2

dydt=3\frac{dy}{dt} = 3

dydx=33t2\frac{dy}{dx} = \frac{3}{3t^2}

=1t2= \frac{1}{t^2}

=t2= t^{-2}

(B) matches with (IV)


For x=logt,y=2t2x = \log t, y = 2t^2:

dxdt=1t\frac{dx}{dt} = \frac{1}{t}

dydt=4t\frac{dy}{dt} = 4t

dydx=4t1/t\frac{dy}{dx} = \frac{4t}{1/t}

=4t×t= 4t \times t

=4t2= 4t^2

(C) matches with (I)


For x=et,y=2tetx = e^t, y = 2te^t:

dxdt=et\frac{dx}{dt} = e^t

Using product rule for y=2t×ety = 2t \times e^t:

dydt=2×et+2t×et\frac{dy}{dt} = 2 \times e^t + 2t \times e^t

=2et(1+t)= 2e^t(1 + t)

dydx=2et(t+1)et\frac{dy}{dx} = \frac{2e^t(t + 1)}{e^t}

=2(t+1)= 2(t + 1)

(D) matches with (II)


Final Matching:

(A) → (III): t2-t^2

(B) → (IV): t2t^{-2}

(C) → (I): 4t24t^2

(D) → (II): 2(t+1)2(t+1)

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question