1. The problem statement, all variables and given/known data I am given a space curve r(t)= t i + sin(t) j and point (pi/2,1). They ask me to find an equation for the circle of curvature. 2. Relevant equations Kappa, T, N, not sure 3. The attempt at a solution So I have found the radius of curvature which is row= 1/kappa= 1 at the given point. I have also found out T which is the unit tangent vector. Do I have to find the unit normal vector also ? How do I write the equation ? will it just be (x-pi/2)^2 + (y-1)^2 = 1 ??