Find the curvature and radius of curvature of the plane

Question

1. Find the curvature K of the curve.

r(t) = e^t cos(t)i + e^t sin(t)j + e^t k.

2. Find the curvature and radius of curvature of the plane curve at the given value of x. (Give your answers correct to 3 significant figures.)

y = 5x + 2/x, x = 3

3. Find the curvature K of the curve. r(t) = 4 cos(πt)i + sin(πt)j