Presentation on theme: "DOUBLE-ANGLE AND HALF-ANGLE FORMULAS. If we want to know a formula for we could use the sum formula. we can trade these places This is called the double."— Presentation transcript:
Half-Angle Formulas We can also derive formulas for an angle divided by 2. As stated it is NOT both + and - but you must figure out where the terminal side of the angle is and put on the appropriate sign for that quadrant.