 Welcome to our session. I'm Kanika and I'm going to help you to solve the following question. The question says, show that the normal at any point theta on the curve, x equals to a cos theta plus a theta sin theta y equals to a sin theta minus a theta cos theta is at the constant distance from the origin. Let's now begin with the solution. We are given that x is equal to a cos theta plus a theta sin theta and y is equal to minus a theta cos theta. With respect to theta we get dx by d theta equals to a into z equal to theta. So dx by d theta is equal to a theta cos theta and y equals to a sin theta minus a with respect to theta we get dy by d theta equals to sin theta and this is equal to so dy by dx is equal to dy by d theta divided by theta. So this is equal to tan theta. We have learnt dy by dx at the point p minus 1 by sin theta is equal to minus cos theta sin theta plus theta sin theta theta plus y sin theta is equal to 0 equation number 1. So we have got equation of normal as x cos theta plus y sin theta equals to 0. Now we have it from the origin. For this we have origin to normal is equal to modulus of 0 into cos theta plus 0 into sin theta minus a divided by equal to a which is up to the given curve is at a constant distance from the origin. So this completes the session. Bye.