Trig – 3/10/2016 Find the exact values of sin 2x, cos 2x, and tan 2x. 313 HW: p , 45, 47, 49, 51, 59, 61 Honors: 89, 91 Today’s Lesson: Half-Angle Formulas

Trig/Pre-Calculus You will: Use the Half-Angle Formulas to rewrite and evaluate trig functions. Today’s Lesson: Half-Angle Formulas

Half-Angle Formulas

Find the exact value of the sin, cos, and tan of 105 o. Always look at the angle on the unit circle! 105 o 210 o In QII, sin is positive.

Find the exact value of the sin, cos, and tan of 105 o. Always look at the angle on the unit circle! 105 o 210 o In QII, cos is negative.

Find the exact value of the sin, cos, and tan of 105 o. Always look at the angle on the unit circle! 105 o 210 o

Find the exact value of the sin, cos, and tan of 75 o. Always look at the angle on the unit circle! 75 o 150 o In QI, sin is positive.

Find the exact value of the sin, cos, and tan of 75 o. Always look at the angle on the unit circle! 75 o 150 o In QI, cos is positive.

Find the exact value of the sin, cos, and tan of 75 o. Always look at the angle on the unit circle! 75 o 150 o

Find the exact values of sin2u, cos2u, and tan2u using the double-angle formula.

Rewrite the expression using the power-reducing formula.