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.
Select your difficulty
Pick more than one for a sheet that mixes them.
The preview can look cramped on a phone. The PDF and printed sheet come out normal.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep
Sigma Prep · sigmaprep.io/worksheets Name Trig Equations With Factoring Date Period Solve each equation on the interval [0, 2π).
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
Sigma Prep · sigmaprep.io/worksheets Name Trig Equations With FactoringAnswer keyVersion 1 Date Period Solve each equation on the interval [0, 2π).
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.
What you can put on this worksheet
- Equations that factor
- Solve on : →
- A double angle first
- Solve on : →
- Quadratics in tangent, secant and cotangent
- Solve on : →
- A half angle next to a whole angle
- Solve on : →
- Squares on both sides, collected first
- Solve on : →
- Four terms, factor by grouping
- Solve on : →
- a sin x + b cos x: divide, or square and check
- Solve on : →