Overview
Read
Next Steps
Overview
Mathematics I
46. CA.M1.S.ID.2
46.3 Solve trigonometric equations using identities
How to Solve Trigonometric Equations Using Identities
A step-by-step approach to solving trigonometric equations using identities, turning tricky mixed-function equations into simple algebra.
What You'll Learn
Trigonometric equations that mix different functions or powers usually need an identity substitution before they can be solved.
The Pythagorean, double-angle, reciprocal, and quotient identities are the ones used most often to rewrite an equation in a single trig function.
Once the equation is rewritten, it can be solved with ordinary algebra, such as factoring or the quadratic formula.
Reference angles and the unit circle turn one base solution into every solution within the given interval.
Always substitute answers back into the original equation to catch extraneous solutions introduced by squaring or dividing.
This Unit Includes
Learning resources
CA Curriculum Aligned