 Hello and welcome to the session, let's work out the following problem it says, prove the following identity where the angles involved are acute angles for which the expression is defined. So let's now move on to the solution and let's start with LHS which is the square root of 1 plus sin A upon 1 minus sin A. Now we have to prove that it is equal to secant A plus tan A. So multiply numerator and denominator by 1 plus sin A, that is the square root of 1 plus sin A whole square upon 1 minus sin A into 1 plus sin A is 1 minus sin square A. Now we have used the formula of A minus B into A plus B which is equal to A square minus B square. Now this is equal to square root of 1 plus sin A whole square upon cos square A 1 minus sin square A is cos square A. Now this is equal to 1 plus sin A upon cos A root gets cancelled with the square, so again equal to 1 upon cos A plus sin A upon cos A 1 upon cos A is secant A sin A upon cos A is tan A which is equal to RHS hence the result is proved. So that's all for this session. Goodbye and take care. Do remember the identities.