MHB How Do You Prove a Vector is Unit Along a Parametric Curve?

[brunette15]

Hey everyone,

I am given the following function f(x,y) = xy+x+y along the curve x(s)=rcos(s/r) and y(s)=rsin(s/r). I have to show that (dx/s)i + (dy/ds)j is a unit vector.

I am unsure where to begin with this :/

Can anyone please give me some hints/ideas on how to approach this question?

 

[Dethrone]

Hi brunette15,

What does it mean when a vector is a unit vector? Let's start by finding $\d{y}{s}$ and $\d{x}{s}$.