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Steps to find d2ydx2\frac{d^2y}{dx^2}dx2d2y​ for x=t2x=t^2x=t2, y=t3y=t^3y=t3?

  1. Find dxdt\frac{dx}{dt}dtdx​ and dydt\frac{dy}{dt}dtdy​. 2. Find dydx=dy/dtdx/dt\frac{dy}{dx} = \frac{dy/dt}{dx/dt}dxdy​=dx/dtdy/dt​. 3. Find ddt(dydx)\frac{d}{dt}(\frac{dy}{dx})dtd​(dxdy​). 4. Divide by dxdt\frac{dx}{dt}dtdx​.
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Steps to find d2ydx2\frac{d^2y}{dx^2}dx2d2y​ for x=t2x=t^2x=t2, y=t3y=t^3y=t3?

  1. Find dxdt\frac{dx}{dt}dtdx​ and dydt\frac{dy}{dt}dtdy​. 2. Find dydx=dy/dtdx/dt\frac{dy}{dx} = \frac{dy/dt}{dx/dt}dxdy​=dx/dtdy/dt​. 3. Find ddt(dydx)\frac{d}{dt}(\frac{dy}{dx})dtd​(dxdy​). 4. Divide by dxdt\frac{dx}{dt}dtdx​.

How to determine where a parametric curve is concave up?

  1. Find d2ydx2\frac{d^2y}{dx^2}dx2d2y​. 2. Set d2ydx2>0\frac{d^2y}{dx^2} > 0dx2d2y​>0. 3. Solve for t.

Find d2ydx2\frac{d^2y}{dx^2}dx2d2y​ if x(t)=t3x(t) = t^3x(t)=t3 and y(t)=t4y(t) = t^4y(t)=t4.

  1. dxdt=3t2\frac{dx}{dt} = 3t^2dtdx​=3t2, dydt=4t3\frac{dy}{dt} = 4t^3dtdy​=4t3. 2. dydx=43t\frac{dy}{dx} = \frac{4}{3}tdxdy​=34​t. 3. ddt(dydx)=43\frac{d}{dt}(\frac{dy}{dx}) = \frac{4}{3}dtd​(dxdy​)=34​. 4. d2ydx2=49t2\frac{d^2y}{dx^2} = \frac{4}{9t^2}dx2d2y​=9t24​.

How to find the second derivative of x=t3−3tx = t^3 - 3tx=t3−3t and y=t2+2t−5y = t^2 + 2t - 5y=t2+2t−5?

  1. Find dxdt=3t2−3\frac{dx}{dt} = 3t^2 - 3dtdx​=3t2−3 and dydt=2t+2\frac{dy}{dt} = 2t + 2dtdy​=2t+2. 2. Find dydx=23(t−1)\frac{dy}{dx} = \frac{2}{3(t-1)}dxdy​=3(t−1)2​. 3. Find ddt(dydx)=−23(t−1)2\frac{d}{dt}(\frac{dy}{dx}) = -\frac{2}{3(t-1)^2}dtd​(dxdy​)=−3(t−1)22​. 4. d2ydx2=−29(t−1)(t2−1)\frac{d^2y}{dx^2} = \frac{-2}{9(t-1)(t^2-1)}dx2d2y​=9(t−1)(t2−1)−2​.

Given x(t)=2(t−sin(t))x(t) = 2(t - sin(t))x(t)=2(t−sin(t)) and y(t)=2(1−cos(t))y(t) = 2(1 - cos(t))y(t)=2(1−cos(t)), show the cycloid is concave down.

  1. Find dxdt=2−2cos(t)\frac{dx}{dt} = 2 - 2cos(t)dtdx​=2−2cos(t) and dydt=2sin(t)\frac{dy}{dt} = 2sin(t)dtdy​=2sin(t). 2. Find dydx=sin(t)1−cos(t)\frac{dy}{dx} = \frac{sin(t)}{1 - cos(t)}dxdy​=1−cos(t)sin(t)​. 3. Find d2ydx2=−12(1−cos(t))2\frac{d^2y}{dx^2} = \frac{-1}{2(1 - cos(t))^2}dx2d2y​=2(1−cos(t))2−1​. 4. Since the second derivative is always negative, the cycloid is always concave down.

How do you simplify cos(t)(1−cos(t))−(sin(t))(sin(t))(1−cos(t))2\frac{cos(t)(1-cos(t))-(sin(t))(sin(t))}{(1-cos(t))^2}(1−cos(t))2cos(t)(1−cos(t))−(sin(t))(sin(t))​?

  1. Expand: cos(t)−cos2(t)−sin2(t)(1−cos(t))2\frac{cos(t) - cos^2(t) - sin^2(t)}{(1 - cos(t))^2}(1−cos(t))2cos(t)−cos2(t)−sin2(t)​. 2. Use sin2(t)+cos2(t)=1sin^2(t) + cos^2(t) = 1sin2(t)+cos2(t)=1: cos(t)−1(1−cos(t))2\frac{cos(t) - 1}{(1 - cos(t))^2}(1−cos(t))2cos(t)−1​. 3. Simplify: −11−cos(t)\frac{-1}{1 - cos(t)}1−cos(t)−1​.

What is the first step in finding the second derivative of x=cos(t)x = cos(t)x=cos(t), y=sin(t)y = sin(t)y=sin(t)?

Find the first derivatives: dxdt=−sin(t)\frac{dx}{dt} = -sin(t)dtdx​=−sin(t) and dydt=cos(t)\frac{dy}{dt} = cos(t)dtdy​=cos(t).

How do you find the slope of the tangent line to a parametric curve at a specific t?

  1. Find dydx=dy/dtdx/dt\frac{dy}{dx} = \frac{dy/dt}{dx/dt}dxdy​=dx/dtdy/dt​. 2. Evaluate dydx\frac{dy}{dx}dxdy​ at the given value of t.

How do you find the t-values where a parametric curve has a horizontal tangent?

  1. Find dydt\frac{dy}{dt}dtdy​. 2. Set dydt=0\frac{dy}{dt} = 0dtdy​=0 and solve for t. 3. Ensure dxdt\frac{dx}{dt}dtdx​ is not also zero at those t-values.

How do you find the t-values where a parametric curve has a vertical tangent?

  1. Find dxdt\frac{dx}{dt}dtdx​. 2. Set dxdt=0\frac{dx}{dt} = 0dtdx​=0 and solve for t. 3. Ensure dydt\frac{dy}{dt}dtdy​ is not also zero at those t-values.

How does dxdt\frac{dx}{dt}dtdx​ and dydt\frac{dy}{dt}dtdy​ relate to dydx\frac{dy}{dx}dxdy​?

dydx\frac{dy}{dx}dxdy​ is found by dividing dydt\frac{dy}{dt}dtdy​ by dxdt\frac{dx}{dt}dtdx​.

What does the sign of the second derivative tell you?

Positive: concave up. Negative: concave down. Zero: possible inflection point.

Why is the chain rule important for second derivatives of parametric equations?

It allows us to express the derivative with respect to x in terms of derivatives with respect to t.

How does finding the second derivative of a parametric function relate to finding the first derivative?

Finding the second derivative involves taking the derivative of the first derivative with respect to the parameter t.

Explain the role of the parameter 't' in parametric equations.

The parameter 't' links the x and y coordinates, defining the curve's position at a given 'time'.

What does concavity tell us about the rate of change of the slope?

Concavity describes whether the slope is increasing (concave up) or decreasing (concave down).

What does a negative second derivative mean in the context of a cycloid?

The cycloid is always concave down, meaning it always curves downward.

Explain the steps involved in finding the second derivative of parametric equations.

Find dx/dt and dy/dt, then find dy/dx, then find the derivative of dy/dx with respect to t, and finally divide by dx/dt.

How do you determine the concavity of a parametric curve?

By analyzing the sign of the second derivative, d2ydx2\frac{d^2y}{dx^2}dx2d2y​.

Explain the relationship between the first and second derivatives in determining the shape of a parametric curve.

The first derivative gives the slope, while the second derivative gives the concavity, which together define the curve's shape.

Define parametric equations.

Functions where independent functions x and y are connected via a parameter t.

What is a second derivative?

The derivative of the first derivative of a function.

What is d2ydx2\frac{d^2y}{dx^2}dx2d2y​?

Notation for the second derivative of y with respect to x.

Define concavity.

The direction of the curve of a function (upward or downward).

What is a cycloid?

A curve traced by a point on a circle as it rolls along a straight line.

Define dydx\frac{dy}{dx}dxdy​ for parametric equations.

The first derivative of y with respect to x, found by dy/dtdx/dt\frac{dy/dt}{dx/dt}dx/dtdy/dt​.

What does the second derivative indicate?

The rate of change of the slope of a function; indicates concavity.

What is the quotient rule?

A rule for finding the derivative of a function that is the ratio of two other functions.

What is a parameter?

An independent variable (often denoted by 't') that relates two dependent variables.

What does it mean for a curve to be concave down?

The curve bends downwards, and its second derivative is negative.