Order the steps for finding a principal value
Read exercise and reference answers
- Steps
- Let y be the inverse value you are asked for
- Rewrite it as the direct trigonometric equation
- Find an angle that satisfies that equation
- Check the angle lies inside the principal value branch
- If it does not, shift to the equivalent angle that does
This is the method your syllabus uses in Examples 1 and 2: name the value, convert to the direct function, find the angle
then check it lies in the principal branch. Source: syllabus Maths Part I, Ch 2 Inverse Trigonometric Functions.