Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Deepak singh 1
go through this link https://192.168.1.121/math2/orthogonal-trajectories/
go through this video link for better understanding. https://www.google.com/search?q=notes+on+Orthogonal+and+oblique+trajectories&oq=notes&aqs=chrome.0.69i59l2j69i57j35i39.2255j0j1&client=ms-android-motorola&sourceid=chrome-mobile&ie=UTF-8#
it will help you