LADIES AND GENTLEMEN, IT IS NOW THE TIME YOU HAVE BEEN WAITING FOR: TRIGONOMETRY
Accel Precalc Unit #5: Introduction to Trigonometry Lesson 1: Sketching Angles EQ: How do you sketch an angle in standard position whose measure is in degrees, pi radians, or decimal degrees?
Identify all key parts of the rectangular coordinate plane. RECALL: Identify all key parts of the rectangular coordinate plane. y-axis Quad II Quad I x-axis origin Quad III Quad IV
New Terms: Variables we will use for naming angles in Trig: alpha beta gamma theta
Angle Measures on the Axes: Degree Measure Radian Measure
Decimal Radian Measure:
Angles Drawn in Standard Position --- initial ray is on x axis; terminal ray may be drawn in a quadrant or on an axis; measure is made from initial ray to terminal ray
Positive Angles Drawn in Standard Position --- counter-clockwise direction from x axis; use an arrow to show direction and number of rotations (if necessary).
Negative Angles Drawn In Standard Position --- clockwise direction from x axis; use an arrow to show direction and number of rotation (if necessary).
Full Rotation vs 54° 320° one rotation = 360˚ = 180˚ What is one rotation through the coordinate plane? one rotation = 360˚ = 180˚ 54° 320° How to Sketch Angles:
-225° -120°
Sketch these angles in standard position.
Day 36 Agenda: Quiz #7 --- 30 minutes
Reference Angles --- positive acute angles; measured from the x axis
OMIT THIS IN YOUR NOTES
State the reference angle for Ex #1 – 5. 7. 8. 9. 10. 11. 25˚ 65˚ 0.28
Coterminal Angles --- have same terminal ray, but different angle measure; infinitely many coterminal angles to one angle.
-42˚+360˚= 318˚ 37˚+360˚= 397˚ -42˚- 360˚= -402˚ 37˚- 360˚= -323˚ Find a positive and negative coterminal angle for each. -42˚+360˚= 318˚ 37˚+360˚= 397˚ -42˚- 360˚= -402˚ 37˚- 360˚= -323˚
RECALL: Complementary Angles --- sum of two angles is 90˚ Supplementary Angles --- sum of two angles is 180˚
DOES NOT EXIST
NEITHER EXISTS
Assignment: textbook p. 291 #5 – 21 odd, 27 – 41 odd