Recent content by FreedayFF

Okay Maple rules do give correct answers. Thanks. But I don't understand why they would give different answers to the "conventional" methods. I'm confused about when to use Maple rules and when not?

I believe your answers are incorrect, as I have all T,B, curvature correct in the attached image above. Your T, however, has the same i value as mine, which is 0 and incorrect.

N = (0,-2/sqrt(148),-12/sqrt(148)) and that gives a wrong answer

N = T'/|T'| so the first term should be 0; but the webwork keeps denying that answer.

Homework Statement Find the unit tangent, normal and binormal vectors T,N,B , and the curvature of the curve x=−4t y=−t2 z=−2t3 at t=1. Homework Equations The Attempt at a Solution I found T=(-4/sqrt(56),-2/sqrt(56),-6/sqrt(56)) which is correct. But I keep getting N wrong...

anyone please?

Homework Statement Kleppner & Kolenkow 7.7 A thin hoop of mass M and radius R is suspended from a string through a point on the rim of the hoop. If the support is turned with high angular velocity \omega, the hoop will spin as shown, with its plane nearly horizontal and its center...

Hahaha silly me spending the whole day trying to prove that it's right, when in fact, it's wrong. Thanks a lot (:

by 3 I meant question 3. I tried to find something that when (A^2 + I)x(something) = kI to prove that (A^2 + I) has an inverse. But have not succeeded in a day. By counter example, do you mean pretending that (A^2 + I) has no inverse and prove it wrong?

can you elaborate the counterexample?

Anyone has any ideas how to do 3 and 4?