Question

Find derivative cosecx .Cot x from first principle

Answer 1

Y = cosecx

we know ,

Lim(∆x→0)∆y/∆x =Lim(∆x→0){f(x+∆x)-f(x)}/∆x

Lim(∆x→0){cosec(x+∆x)-cosecx}/∆x

use L—Hispital rule ,

dy/dx =-cosecx.cotx