Recent content by HaniZaheer

Alright, thanks a lot

Proof: If either x or y is zero, then the inequality |x · y| ≤ | x | | y | is trivially correct because both sides are zero. If neither x nor y is zero, then by x · y = | x | | y | cos θ, |x · y|=| x | | y | cos θ | ≤ | x | | y | since -1 ≤ cos θ ≤ 1 How valid is this a proof of the...

Thanks for the help. But the form of the equations the question was looking for was to sort of not use derivative and instead use vector gradient. The solution to the problem is as follows: $$\vec t \cdot \nabla \vec t = \frac {\vec n} {\rho}$$ and $$\vec t \cdot \nabla \vec b = - \vec \tau \vec...

Hey. I am trying to self study from "Theoretical Physics" by Georg Joos and am stuck on this particular question. The question asks for the reader to write the equations $$\frac {dt} {ds} = \frac {\vec n} {\rho}$$ and $$\frac {db} {ds} = - \tau \vec n$$ using vector gradient. I don't even know...