Homework SourseWhen finding lenth of a curve how do I know when to use inte
When finding lenth of a curve how do I know when to use integral a to b square root((dx/dt)^2 + (dy/dt)^2)dt or integral a to b square root(1+(dy/dx)^2....What should I notice to use the appropriate one
Solution
if X & Y are funtions of t ( means X = f(t) & Y= g(t) ..we use integral a to b square root((dx/dt)^2 + (dy/dt)^2)dt ex : x= acos(theta) , Y= bsin (theta) if X= f(y) or Y= g(x) the we use integral a to b square root(1+(dy/dx)^2 ex : Y= ax^3
