 Hi, and welcome to the session. I am Deepika here. Let's discuss the question. Find the principal value of tan inverse minus 1. We know that the range of the principal value branch of tan inverse is my open interval minus pi by 2 to pi by 2. So this is the key idea behind this question. So let's start the solution is equal to y then is equal to minus tan pi by 4 to minus tan theta. So this is equal to tan of minus pi by 4. The key idea, the range of the principal value branch minus pi by 2 to pi by 2 and is equal to minus 1. So therefore, the principal value tar for the above question. That is, principal value of tan inverse minus 1 is minus pi by 4. So I hope the question is clear to you. Why and enjoy yourself?