Find all possible values of $z$ such that $\cos z=\frac{3}{4}+\frac{i}{4}$.
37108
Solve $\cos(z)=\frac 34+\frac i4$
66317
How to solve $z^3+z+1=0$?
55179
How to find the exact value of $ \cos(36^\circ) $?
52018
Can $\frac{\sqrt{3}}{\sin20^{\circ}}-\frac{1}{\cos20^{\circ}}$ have two values?
34709
Complex numbers - roots of unity
60774
Find the value of : $\cos x \cos 2x...\cos 999x$ given that $x=\frac {2\pi}{1999}$
6595
Solve for positive integers: $\frac{4}{13}=\frac{1}{x}+\frac{1}{y}+\frac{1}{z}$
108801
Given that $xyz=1$, prove that $\frac{x}{1+x^4}+\frac{y}{1+y^4}+\frac{z}{1+z^4}\le \frac{3}{2}$
31317
If we know $x+y+z=1$, $x^2+y^2+z^2=2$, and $x^3+y^3+z^3=3$, how to find $x^4+y^4+z^4$?
38160
Number of roots of $z^4+z^3+4z^2+2z+3=0$ in each quadrants
105336
What are the solutions to $z^4+1=0$?
104542
Evaluate $\frac{1}{3}+\frac{1}{4}\frac{1}{2!}+\frac{1}{5}\frac{1}{3!}+\dots$
74143
Simplifying and evaluating $\cot 70^\circ+4\cos 70^\circ$
13085
Evaluate $ 1 + \frac{1}{3}\frac{1}{4}+\frac{1}{5}\frac{1}{4^2}+\frac{1}{7}\frac{1}{4^3}+\dots$
105117
$1 + \frac{1}{3}\frac{1}{4} + \frac{1}{5}\frac{1}{4^2} + \frac{1}{7}\frac{1}{4^3} + ..........$
142076
$c$ is a complex number that satisyfing $(c+\frac{1}{c}+1)(c+\frac{1}{c}) = 1$
107067
Finding the argument of $z=1-\cos(2\theta)-i\sin(2\theta)$