What's the consultant result of $x_1(t)=3\cos(2t+\pi/2)$ and $x_2(t)=4\cos(2t)$?
55436
Why does $A\sin{k(x+c)}=a\sin{kx}+b\cos{kx}$ imply that $A=\sqrt{a^2+b^2}$ and $\tan{c}=-b/a$?
30429
How to prove $\cos \frac{2\pi }{5}=\frac{-1+\sqrt{5}}{4}$?
75279
Reversing the $T(n) = \frac{n(n+1)}{2}$ formula
44438
Prove : $\frac{\cos(x_1) +\cos(x_2) +\cdots+\cos(x_{10})}{\sin(x_1) +\sin(x_2) +\cdots+\sin(x_{10})} \ge 3$
86367
Computing $f(x)$ if $\int_1^{xy} f(t) dt = y \int_1^x f(t) dt + x\int_1^y f(t) dt$ and $f(1) = 3$
72039
Compute $\int_0^\infty\frac{\cos(xt)}{1+t^2}dt$
46353
Proof that $\cos(\pi/3)=1/2$
80015
$Tr(A^2)=Tr(A^3)=Tr(A^4)$ then find $Tr(A)$
143428
How to sum $\sum_{x=0}^{N-1} \cos{\left( \frac{2\pi x}{N} \right)}^{2}$?
154172
Finding $\tan t$ if $t=\sum\tan^{-1}(1/2t^2)$
9587
If $f(t) = 1+ \frac{1}{2} +\frac{1}{3}+....+\frac{1}{t}$, find $\sum^n_{r=1} (2r+1)f(r)$ in terms of $f(n)$
9390
$ \int_1^2\int_1^2 \int_1^2 \int_1^2 \frac{x_1+x_2+x_3-x_4}{x_1+x_2+x_3+x_4}dx_1dx_2dx_3dx_4 $
56934
How do we prove $\cos(\pi/5) - \cos(2\pi/5) = 0.5$ ?.
36586
Evaluating $\frac{1}{2\pi}\int_{0}^{2\pi}\frac{1}{1-2t\cos\theta +t^2}d\theta$
40534
What is $(-1)^{\frac{2}{3}}$?
109706
Fast way to come up with solutions to $x(x-1)(x-2)(x-3)=1$?
104384
Trigonometric identity: $\frac {\tan\theta}{1-\cot\theta}+\frac {\cot\theta}{1-\tan\theta} =1+\sec\theta\cdot\csc\theta$