1. The problem statement, all variables and given/known data Question: "Find the unit tangent, normal and binormal vectors T, N, B, and the curvature of the curve x = 4t, y = -3t^2, z = -4t^3 at t = 1." Answer: T = 0.285714285714286 i - 0.428571428571429 j - 0.857142857142857 k N = -0.75644794981871 i + 0.448265451744421 - 0.476282042478447 k B = 0.588348405414552 i + 0.784464540552736 j - 0.196116135138184 ϰ = 0.0445978383113072 2. Relevant equations N = dT/dt / |dT/dt| 3. The attempt at a solution I tried to use the equation from the "Relevant equations" part above. I know there are alternative ways but I want to figure out what I am doing wrong for this method. I (successfully) get the unit tangent vector to be: T = (4 i - 6t j - 12t^2 k)/sqrt(4^2 + 6^2 * t^2 + 12^2 * t^4) T = 2/7 i - 3/7 * t j - 6/7 * t^2 k I (unsuccessfully) get the unit normal vector to be: N = (3/7 i - 12/7*t k)/sqrt( (3/7)^2 + (12/7)^2 * t^2) What am I doing wrong? Any input would be greatly appreciated! Thanks in advance!