Trig equations with factoring worksheet
Treat sine or cosine as the variable and it is a quadratic like any other. When both appear squared, one Pythagorean substitution gets everything back into a single ratio first.
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Sigma Prep · sigmaprep.io/worksheets Name Trig Equations With FactoringDate Period Solve each equation on the interval [0, 2\pi). Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
Sigma Prep · sigmaprep.io/worksheets Name Trig Equations With FactoringAnswer keyVersion 1Date Period Solve each equation on the interval [0, 2\pi). Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
How to do these
- It factors as (2 sin x + 1)(sin x - 1).
- So sine is minus one half, or 1.
- That is three angles on one turn.
The answer is .
Where students go wrong
Dividing both sides by sin x to get rid of it. That throws away every solution where sine is zero. Factor it out instead and set both factors to zero.
Also called factoring trig equations, quadratic trig equations or Pythagorean identity.