Math Problem Statement

x is equal to t square, y is equal to t cube. Find double differentiation of dy upon dx.

Solution

Given the parametric equations:

x=t2andy=t3x = t^2 \quad \text{and} \quad y = t^3

To find the second derivative d2ydx2\frac{d^2y}{dx^2}, we first need to determine dydx\frac{dy}{dx}.

Step 1: Find dydt\frac{dy}{dt} and dxdt\frac{dx}{dt}

dxdt=d(t2)dt=2t\frac{dx}{dt} = \frac{d(t^2)}{dt} = 2t dydt=d(t3)dt=3t2\frac{dy}{dt} = \frac{d(t^3)}{dt} = 3t^2

Step 2: Find dydx\frac{dy}{dx}

Using the chain rule: dydx=dydtdxdt=3t22t=3t2\frac{dy}{dx} = \frac{\frac{dy}{dt}}{\frac{dx}{dt}} = \frac{3t^2}{2t} = \frac{3t}{2}

Step 3: Find d2ydx2\frac{d^2y}{dx^2}

To find the second derivative, we differentiate dydx\frac{dy}{dx} with respect to tt, and then divide by dxdt\frac{dx}{dt}:

ddt(dydx)=ddt(3t2)=32\frac{d}{dt}\left(\frac{dy}{dx}\right) = \frac{d}{dt}\left(\frac{3t}{2}\right) = \frac{3}{2}

d2ydx2=ddt(dydx)dxdt=322t=34t\frac{d^2y}{dx^2} = \frac{\frac{d}{dt}\left(\frac{dy}{dx}\right)}{\frac{dx}{dt}} = \frac{\frac{3}{2}}{2t} = \frac{3}{4t}

Thus, the second derivative d2ydx2\frac{d^2y}{dx^2} is:

34t\boxed{\frac{3}{4t}}

Would you like more details or have any further questions?

Here are five related questions for further exploration:

  1. How do you interpret the physical meaning of d2ydx2\frac{d^2y}{dx^2} in the context of parametric equations?
  2. What would d2ydx2\frac{d^2y}{dx^2} be if x=t3x = t^3 and y=t4y = t^4?
  3. How does changing the parametric equations affect the curvature of the curve described by yy and xx?
  4. Can you find the point of inflection for the curve defined by these parametric equations?
  5. What happens to d2ydx2\frac{d^2y}{dx^2} as tt approaches zero?

Tip: When working with parametric equations, always remember to apply the chain rule carefully, especially when transitioning between different derivatives.

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Math Problem Analysis

Mathematical Concepts

Parametric Equations
Differentiation
Chain Rule

Formulas

Chain Rule for Differentiation

Theorems

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Suitable Grade Level

Grades 11-12