Connecting Two Endpoints with Zero Curvature and Slope Using a Cubic Curve

In summary, to find a curve that connects two endpoints with zero curvature and slope, you can use the equation y = ax^5 + bx^3 + cx and set up three equations to solve for the values of a, b, and c. By substituting the x and y coordinates of the endpoints and solving the equations, you can determine the values of a, b, and c and find the desired curve.
  • #1
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Homework Statement


A line segment extends horizontally to the left from (-1,-1) and another line extends horizontally to the right from the point (1,1) find a curve of the form y=ax^5+bx^3+cx that connects the two endpoints so that the curvature and slope are zero at the endpoints


Homework Equations





The Attempt at a Solution


Not sure even where to start
 
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  • #2
If y=ax^5+bx^3+cx is going to connect the two endpoints, then if you substitute 1 for x what should you get for y? You should get an equation that has to be satisfied by a, b and c. You want to get enough equations in those three unknowns to determine them. The slope is y'. Use that. What's an expression for the curvature? Use that too.
 
  • #3
y = ax^5 + bx^3 + cx

You take the first derivative which will give you the slope of the tangent line
Y' = 5ax^4 +3bx^2 +c

You know that Y' = 0

Take the second derivative which relates to curvature
Y'' = 20ax^3 + 6bx

You should know Y'' = 0

If you consider the point (1,1) your x = 1 and your y = 1
You can now set up three equations
a+b+c = 1
5a + 3b + c = 0
20a +6b = 0

if you solve these equations for a, b, and c
you get
a = 3/8
b = -5/4
c = 15/8

so the equation is
y = 3/8 x^5 - 5/4 x^3 + 15/8 x
 

Related to Connecting Two Endpoints with Zero Curvature and Slope Using a Cubic Curve

1. What is the concept of curvature in Calculus 3?

In Calculus 3, curvature refers to the measure of how much a curve deviates from a straight line. It is a fundamental concept in multivariable calculus and is used to analyze the behavior of curves and surfaces in three-dimensional space.

2. How is curvature calculated in Calculus 3?

The most common method for calculating curvature in Calculus 3 is by using the formula k = |T'(s)|/|r'(s)|, where k is the curvature, T'(s) is the derivative of the unit tangent vector, and r'(s) is the derivative of the position vector. Alternatively, curvature can also be calculated using the second derivative of the position vector, which is known as the curvature vector.

3. What is the relationship between curvature and radius of curvature?

The radius of curvature, denoted by ρ, is the reciprocal of the curvature and represents the radius of the circle that best approximates the curve at a given point. In other words, as the curvature increases, the radius of curvature decreases and vice versa.

4. What is the significance of curvature in real-world applications?

Curvature plays a crucial role in many real-world applications, such as engineering, physics, and computer graphics. It is used to analyze the behavior of objects moving through three-dimensional space, such as the trajectory of a satellite or the shape of a rollercoaster. Additionally, curvature is essential for understanding the properties of surfaces, such as the shape of a lens or the surface of a sphere.

5. How does the curvature of a curve affect its shape?

The curvature of a curve directly affects its shape. A curve with a high curvature will have a sharper turn or bend, while a curve with a low curvature will have a more gradual change in direction. The sign of the curvature (positive or negative) also determines the direction of the curve, with positive curvature indicating a curve that is concave up and negative curvature indicating a curve that is concave down.

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