let a=(3-4costheta)i-(4sintheta)j and b=(4-5sintheta)i-(5costheta)j for theta belongs to (0,pi/2)

[@UdayS-6]

👌🏻

[@chiragprakash2823]

👍

[@BhumikabaiBhumikabai]

👍👍

[@sushmithapremkumar7213]

Nice explanation sir

[@Chiku_1988]

👌👍

[@su-jax]

Understood Sir 👌👍

[@manasagangaraja]

Very nice explanation sir

[@Hindutva_Hindu013]

Super sir.❤ understood Sir

[@divyadas_2504]

Understood sir 👍🏻

[@Ravikanth-283]

❤❤❤ Nice explanation sir ❤❤❤

[@pritham07]

Superb explanation Sir ⚡️

[@srikanta.y.r.3110]

Got it sir 👌

[@aratipandit579]

I didn't understand how u got its decreasg func....shldnt u 1st check by differentiating it?

[@JEEMATHSADDA]

By substituting the given interval only, we will get a clarity. Like cosx is decreasing in interval [0,pi/2] (cos0=1,cos(pi/2)=0)
Like this , i explained in video by taking limits because in question it is open interval

[@rabiprakashsha3924]

Your logic is wrong why because f'(theta ) < 0 only for theta belong to ( 0.65,1.57) in this interval it is decreasing but in (0,0.65) derrivative > 0 please don't misguide the students with wrong logics.

[@JEEMATHSADDA]

Can you please tell me , is f(x)=x^3 is strictly increasing by using your concept of first derivative???

[@shobhakruthika81]

Nice explanation sir

[@BarryM-c1r]

Understood Sir 👌