Sine representation of cosine
5080
How can we sum up $\sin$ and $\cos$ series when the angles are in arithmetic progression?
67988
Trigonometric curiosity
148207
Express $\cos 6\theta $ in terms of $\cos \theta$
122705
Solution of trigonometric equation $0 = x\cos(x)+2$
27513
Trigonometric bounds
60709
How do I get $\cos{\theta} \lt \frac{\sin{\theta}}{\theta} \lt 1$?
71360
How do I represent the following equations
99328
Value of $\sin (2^\circ)\cdot \sin (4^\circ)\cdot \sin (6^\circ)\cdots \sin (90^\circ) $
105774
How is $ \cos (\alpha / \beta) $ expressed in terms of $\cos \alpha $ and $ \cos \beta $?
101765
How to memorize the families that are $\sin$, $\cos$, and $\tan$ of $\pi$ over something?
99221
Orthogonality lemma sine and cosine
73538
solving $\cos z + \sin z = i$
150928
Summation of a trigonometric series - $\frac{\sin n}{n}$
34590
Fourier series of Log sine and Log cos
12841
Ratio of sines given, find ratio of cosines?
18967
Linear independence of $\sin(x)$ and $\cos(x)$
115090
Alternative definition of hyperbolic cosine without relying on exponential function