Radius and centre of curvature

Can anyone say

why it is showing inf as output as shown in the screenshot attached, when I ask radius and centre of curvature for sqrt(X)+sqrt(y)==sqrt(a),when x = 3???

Why it is not showing a numerical value???

Kindly solve this problem.

[KALYAN ACHARJYA]

Maybe you forgot to attach the screenshot?

[Subramani Nagaraj]

Sorry sir I thought I had attached the screenshot. Now I had attached it.

Answer 1

[Divija Aleti]

Hi Nagaraj,

You will have to first change your equation to the form of y = f(x) and then use the formulae to find the radius and center of curvature. The code is given below for your reference:

syms y(x) a
y(x) = (sqrt(a)-sqrt(x))^2; % Re-arranged the equation
x1 = 3;
c1 = x - (diff(y,x)*(1+(diff(y,x))^2))/diff(y,x,2);
c1 = c1(x1) % Found x-coordinate of center of curvature
y1 = y(x1);
c2 = y + (1+(diff(y,x))^2)/diff(y,x,2);
c2 = c2(y1) % Found y-coordinate of center of curvature
Center = [c1,c2];
Point = [x1,y1];
Radius = ((x1-c1)^2 + (y1-c2)^2) % Distance between the point and the center gives radius of curvature

For additional information on the 'diff' function, refer to the following link:

Differentiate symbolic expression or function - MATLAB diff (mathworks.com)

Regards,

Divija

[Subramani Nagaraj]

Thank you so much madam for solving my problem.

[Image Analyst]

@Divya:

If you have any more questions, then attach your data and code to read it in with the paperclip icon, in a new question, after you read this:

TUTORIAL: How to ask a question (on Answers) and get a fast answer

You can give a link in your question to this question.

[Image Analyst]

@Divya I think you ignored my last comment totally. Let me give instructions step by step.

1. Read TUTORIAL: How to ask a question (on Answers) and get a fast answer
2. Click on the Ask link above (right under the blue MATLAB Answers banner) and fill out the form to post a totally new question (not here).
3. In the edit box, click the paperclip icon and attach your .m file, and any data files that need to be read in.
4. Click the "Post Question" button to submit your question. Then it will appear on the list.