Trigonometry

## One Cycle of a Trigonometric Function

Integral of a Complex Exponential Consider the integral $\int_0^{2 \pi} d\theta e^{i \theta}$. […]

Differentiation

## Differentiating the Sine Function

From this post, one type of derivative is $\lim_{\Delta x\rightarrow0^+}\frac{f(a+\Delta x)-f(a)}{\Delta x}\equiv\frac{df(x)}{dx}\big|_{a^+}$ To be consistent with […]

## The sine function divided by its angle, and a certain limit

What is $\lim_{x\rightarrow0} \frac{\sin x}{x}$ ? Recall the definition of a limit, repeated here for reference […]

Trigonometry