Day 3 · Introduction to Inverse Trigonometric Functions

Inverse trigonometric functions, like sin⁻¹(x), find the angle from a trig ratio — the opposite of sin(x), which finds the ratio from an angle.

The domain of sin⁻¹(x) is [-1, 1], because sin(x) only ever takes values between -1 and 1.

sin⁻¹(1) = π/2, because sin(π/2) = 1. And tan⁻¹(1) = π/4, because tan(π/4) = 1.

Activity: Try finding cos⁻¹(1) and sin⁻¹(0) using angles you already know.