--description--

In this video, you will learn about trigonometric identities.

--questions--

--text--

Why is the second equation in the first example called an identity?

--answers--

Its tangent and cotangent functions are equal.

---

Its cosine and secant functions are equal.

---

It holds all values of the variable.

---

It holds none of the values of the variable.

--video-solution--

3