Area of a Circle using Slicing and Definite Integrals

[@NQTY]

this is wild, thank you so much for being so detailed and sequential

[@ProtoflareZ]

Excellent video, thank you for making it.

[@LEEHYORISARANGHEIO]

Where is this angle theta taken from in the right angle triangle sir ?? And why??

[@Phillydogaz1]

I'm using trig substitution to solve the integral, so theta is just a dummy variable, it doesn't have any practical meaning in the diagram.

[@LEEHYORISARANGHEIO]

So, since it is just dummy vrble,... Can i make let y=Rcostheta then???

[@Phillydogaz1]

@@LEEHYORISARANGHEIO you can, but doing a trig sub we usually use sin for our sub b/c it's derivative is positive, derivative of cos is negative, introduces a negative sign to integral, not a big deal, just something to remember.