New posts in trigonometry

Law of Cosines: Proof Without Words

geometry trigonometry

Testing continuity of the function $f(x) = \lim\limits_{n \to \infty} \frac{x}{(2\sin{x})^{2n}+1} \ \text{for} \ x \in \mathbb{R}$

calculus trigonometry limits

Is is mathematically correct to write $\frac{h>2}{l<4}\neq\frac{1}{2}$ therefore $\sin^{-1}\frac{h>2}{l<4}\neq30^{\circ}$?

algebra-precalculus trigonometry

how to find this limit $\lim_{x\rightarrow 0} \frac{\sin x^2}{ \ln ( \cos x^2 \cos x + \sin x^2 \sin x)} = -2$ without using L'Hôpital's rule

trigonometry limits

Find $\sin^3 a + \cos^3 a$, if $\sin a + \cos a$ is known

Is there a pythagorean triple such that all angles of the corresponding triangle are simple fractions of $\pi$?

geometry trigonometry irrational-numbers transcendental-numbers

tricky system of trigonometric equations

Maximizing an angle based on certain constraints

geometry trigonometry euclidean-geometry circles angle

$\sin 4x +\sqrt{3} \sin 3 x + \sin 2 x=0$

Simple Trig Equations - Why is it Wrong to Cancel Trig Terms?

algebra-precalculus trigonometry quadratics

Finite Series $\sum_{k=1}^{n-1}\frac1{1-\cos(\frac{2k\pi}{n})}$

real-analysis sequences-and-series trigonometry summation closed-form

Determine the argument of the complex $Z$

trigonometry complex-numbers

Does there exist a tool to construct a perfect sine wave?

geometry trigonometry recreational-mathematics puzzle geometric-construction

Why does the plot of $f(x)=|\cos x|-|\sin x|$ look almost piecewise linear?

real-analysis calculus algebra-precalculus trigonometry

Is there an explicit formula that gives the value of $\sqrt{2+\sqrt{2+\sqrt{2+\cdots}}}$ for $n$ square roots? [duplicate]

calculus algebra-precalculus trigonometry substitution nested-radicals

Simplifying $\frac{\pi(1-\cos(\pi x))\cos(\pi x)-\pi\sin^2(\pi x)}{(1-\cos(\pi x))^2}$ to $\frac\pi{\cos\pi x-1}$

algebra-precalculus trigonometry

A contradictory integral: $\int \sin x \cos x \, \mathrm dx$

integration trigonometry fake-proofs

Stuck at proving whether the sequence is convergent or not

real-analysis sequences-and-series trigonometry convergence-divergence limsup-and-liminf

Evaluating $\sum_{n=0}^{\infty}{\sin^{3}\left(3^{n}\right) \over 3^{n}}$

sequences-and-series trigonometry

Find $\lim_{x\to \frac\pi2}\frac{\tan2x}{x-\frac\pi2}$ without l'hopital's rule.

calculus limits trigonometry limits-without-lhopital