Formula deep page
Double Angle
sin2A = 2sinAcosA
cos2A = cos²A - sin²A = 1-2sin²A
This formula belongs to the chapter "Trigonometric Functions" in Class 11 Mathematics. Use it after identifying the right variables, matching the chapter context, and writing the substitution clearly.
How to use it
- Identify the quantity you need to find.
- Check the related variables and units from the question.
- Substitute values carefully into the formula.
- Simplify step by step and write the final statement.
Worked cue
sin60°=sin(2×30°)=2×sin30°×cos30°=2×(1/2)×(√3/2)=√3/2 ✓