Solving for Exact Trigonometric Values Using the Unit Circle 15 April 2011

Reference Angles Reference angles make it easier to find exact values of trig functions in the unit circle

Reference Angles, cont. Always

Solving for Reference Angles Step 1: _____________________________ _________________ (Remember, coterminal angles are positive and less than 2π.) Step 2: _____________________________ (if less than 2π) ______________________ (if greater than 360° or 2π) Step 3: _____________________________ ____________ This is the reference angle!!!!

Example:

Example:

Example:

Your Turn:

Your Turn:

Your Turn:

Your Turn:

Your Turn:

Solving for Exact Trig Values Step 1: ____________________________ (Note the quadrant) Step 2: ________________________________ Step 3: ________________________________ _____________________(Make sure the signs match the quadrant!) Step 5: ________________________________ Step 6: ___________________ the denominator if necessary

Example: Reference Angle: Special Triangle:

Example: Coordinates: Tangent: Sine: Cosine:

Example: Reference Angle: Special Triangle:

Example: Coordinates: Tangent: Sine: Cosine:

Example: Reference Angle: Special Triangle:

Example: Coordinates: Tangent: Sine: Cosine: