How to prove U•V = |U|•|V|cos(θ), if θ is the angle between |U| and |V|
123392
How does $cos(x) = \frac{\vec{v} \cdot \vec{w}}{|\vec{v}| \cdot |\vec{w}|}$ make sense?
118501
Proving the length of a circle's arc is proportional to the size of the angle
122663
Proving $T$ and $U$ are equal if I know $(X,T)$ and $(X,U)$ are hausdorff and compact
114411
Simple Proof of the Euler Identity $\exp{i\theta}=\cos{\theta}+i\sin{\theta}$
40596
Proving a relation between inradius ,circumradius and exradii in a triangle
100788
Proving Newton's identities
20581
How to show that $\Gamma\vdash (\varphi\to\neg\varphi)\to\varphi$?
54512
How do I prove: $\cos (\theta + 90^\circ) \equiv - \sin \theta $
145632
Proving $\frac{1}{\cos^2\alpha}<\frac{\tan\beta-\tan\alpha}{\beta-\alpha}<\frac{1}{\cos^2\beta}$
85872
Prove $1 + \tan^2\theta = \sec^2\theta$
20863
how do I prove this inequallity?
60761
Proof: $\cos^p (\theta) \le \cos(p\theta)$
46669
How can I prove these are the adjoint operators?
143072
Proving $|\sin x - \sin y| < |x - y|$
77891
$(U\circ T)^{*} = T^{*}\circ U^{*}$
35244
Prove $\sin^2\theta + \cos^2\theta = 1$
131609
Prove that $Au\cdot v = u\cdot A^Tv$