How to solve pls once show step..

i think you can calculate these conditions . if yes then give a thums up .keep practicing

you need to calculate only (rt-s^2) at these points and signs of r and t

see this video. https://youtu.be/odkaPgWPQGo

i calculated the values of alpha and beta. since you have given the point where you want to check extremas so you need to calculate the conditions. https://tutorial.math.lamar....

see this