CK-12 Foundation
Finding Exact Trigonometric Values Using Double Angle Identities: Trig Values Using Double and Half Angle Formulas
The more you know, the more you can learn. Scholars apply the double angle and half angle formulas to determine trig values based on known values. They use an interactive that provides sine and cosine values to aid calculations.
CK-12 Foundation
Half Angle Formulas: Half-Angle Formulas
Slide the resource into your lesson plans. Young mathematicians use a slider to move a movie screen to the right position for optimal viewing. Along the way, they learn to apply the half angle formulas.