Aug 28, 2016 · 1) $\cos^2 x + \sin^2 x = 1$ So $2 \cos^2 x = 1$ So $\cos x = \sin x = \pm \sqrt{\frac 12}$ 2) $\sin x$ is the adjacent side of a right triangle.

Oct 14, 2018 · How can I know the values of: $\sin(i)$ and $\cos(i)$? I am studying complex variables for the first time, so I asked myself if these functions exist (considering that the complex plane can be see...

Aug 30, 2020 · Trigonometric Functions (And Functions In General) Aren't Considered As Operators, But As Functions Instead, So, Technically Speaking, They Can't Belong In The Order Of Operation (A.K.A. BODMAS/PEDMAS/BIDMAS).

The sine and cosine are related to the two legs of a right triangle; they are the ratio of the leg opposite the angle to the hypotenuse and the ratio of the leg adjacent to the angle to the hypotenuse, respectively.

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Oct 6, 2014 · How do you prove the following: Pythagorean trigonometric identity. For all $\theta\in[0,2\pi]$ it holds that $$ \sin^2\theta+\cos^2\theta=1.$$ I'm curious to know of the different ways of provin...

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Jul 15, 2019 · $\begingroup$ Because we have a homogeneous second order linear differentiation equation where the general solution is $y(x) = c_1\sin(x) + c_2\cos(x)$.

Mar 13, 2015 · One thing I've found useful is having a mental picture of the $\sin$ and $\cos$ functions. If you draw your vector and split it up into components like so:

Sep 18, 2015 · A simple way to do the indefinite integral is this $$ \int \underbrace{\sin(nx)}_{\displaystyle u} \Big(\underbrace{\cos(nx)\,dx}_{\dfrac{du} n}\Big) = \frac 1 n \int ...