How To Find The Radius Of A Curvature

The radius of a curvature is the radius of a circle drawn through parts of a curve. This radius can be used for a variety of mechanical, physical and optical calculations. Finding the radius requires the use of calculus. The formula for finding the radius of a curvature is:

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{[1+(dy/dx)^2]^3/2} / |d^2y/dx^2|

To calculate the radius of a curvature, take the equation of your curve and use the radius of a curvature formula to solve for a variable "x" at a point along the curve.

Step 1

Calculate the derivative, dy/dx, of your curve. Using this result, calculate the second derivative, d^2y/dx,

Step 2

Square the first derivative, dy/dx, and plug the result into the formula for finding the radius of a curvature. Put the result into the formula at (dy/dx)^2.

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Step 3

Plug the second derivative of your curve equation into the formula for finding the radius of a curvature. Put the second derivative into the formula at d^2y/dx^2.

Step 4

Solve the equation for a point "x" along your curve by replacing the variable "x" with a numerical value. Use a calculator to speed your calculations.

Things Needed

  • Pencil
  • Paper
  • Calculator
  • Equation of a curve

TL;DR (Too Long; Didn't Read)

Some advanced graphing calculators have a built-in function that will calculate the radius of a curvature automatically. If you have a graphing calculator with this function, use it to check your work.

Warning

Always check your work to make sure it is accurate.

Cite This Article

MLA

Nagel, William. "How To Find The Radius Of A Curvature" sciencing.com, https://www.sciencing.com/how-to-find-the-radius-of-a-curvature-12751649/. 30 May 2013.

APA

Nagel, William. (2013, May 30). How To Find The Radius Of A Curvature. sciencing.com. Retrieved from https://www.sciencing.com/how-to-find-the-radius-of-a-curvature-12751649/

Chicago

Nagel, William. How To Find The Radius Of A Curvature last modified March 24, 2022. https://www.sciencing.com/how-to-find-the-radius-of-a-curvature-12751649/

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