$\cos 3+\cos 7+...+\cos(2 n+3)= $to a compact formula
9479
$\sum \cos$ when angles are in arithmetic progression
44119
Prove that $\cos (A + B)\cos (A - B) = {\cos ^2}A - {\sin ^2}B$
96367
Intuition of Addition Formula for Sine and Cosine
118408
Equation with cos and product
148632
How to expand $\cos nx$ with $\cos x$?
17188
Simplify $\cos(n \pi)$ and $\sin(n \pi)$ when n is an integer
482
Express $1 + \frac {1}{2} \binom{n}{1} + \frac {1}{3} \binom{n}{2} + \dotsb + \frac{1}{n + 1}\binom{n}{n}$ in a simplifed form
156597
Proving a reduction formula for the antiderivative of $\cos^n(x)$
115719
Find the possible values of |A + B + C |
62271
Find the sum of the series: $\cos^3 \alpha +\cos^3 {3\alpha} + \cos^3 {5\alpha}+....+\cos^3 {(2n-1)\alpha}$.
48956
Simplify $\arctan (\frac{1}{2}\tan (2A)) + \arctan (\cot (A)) + \arctan (\cot ^{3}(A)) $
55128
Evaluation of $\sin \frac{\pi}{7}\cdot \sin \frac{2\pi}{7}\cdot \sin \frac{3\pi}{7}$
30518
Formula for $\sum_{k=1}^n \frac{1}{k(k+1)(k+2)}$?
111295
Prove that $a^7 + b^7 + c^7 \geq a^4b^3 + b^4c^3 + c^4a^3$
148207
Express $\cos 6\theta $ in terms of $\cos \theta$
121279
Proving an Combination formula $ \binom{n}{k} = \binom{n-1}{k}+\binom{n-1}{k-1}$
562
Formula for calculating $\sum_{n=0}^{m}nr^n$