Proof explanation for a sum of sines
5080
How can we sum up $\sin$ and $\cos$ series when the angles are in arithmetic progression?
103501
Question about a normal equation proof
24656
Proving that $\frac{\csc\theta}{\cot\theta}-\frac{\cot\theta}{\csc\theta}=\tan\theta\sin\theta$
42424
Riemann sum of $\sin(x)$
59208
How to explain the equation about summation?
31387
Why is $\sin{x} = x -\frac{x^3}{3!} + \frac{x^5}{5!} - \cdots$ for all $x$?
35244
Prove $\sin^2\theta + \cos^2\theta = 1$
135543
Proof of Angles going beyond 90 degrees in Trigonometry
106355
How to prove Lagrange trigonometric identity
91744
Proving sum of sines is periodic when ratio of their frequencies is rational using differentation
145500
Finite Series - reciprocals of sines
13297
Prove the following trigonometric identity without a calculator involved
26790
Proving the geometric sum formula by induction
143072
Proving $|\sin x - \sin y| < |x - y|$
129880
Proving $\frac{1}{\sin^{2}\frac{\pi}{14}} + \frac{1}{\sin^{2}\frac{3\pi}{14}} + \frac{1}{\sin^{2}\frac{5\pi}{14}} = 24$
116580
Prove by induction: $\sin{x}+\sin{3x}+\dots+\sin{(2n-1)x}=\frac{\sin^2{nx}}{\sin{x}}$
127380
Use vectors to prove $\cos(\beta - \alpha) = \cos \alpha \cos\beta + \sin\alpha \sin\beta$