Trigonometric identities are powerful tools for simplifying complex equations in math and science. Three core ...

Sin, cos and tan are commonly used abbreviations for the three trigonometric functions sine, cosine and tangent. ... (in this example, 5/7). tan⁻¹ is the inverse function of tan.

Interestingly enough, the trigonometric functions that define those relationships are also closely tied to circles. ... Next, think about the relationship between sine, cosine and the circle.