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Sec 2.1 Trigonometric Functions of Acute Angles. October 1, 2012. Warm – Up (10/1). Right Triangle w/ Respect to Angle A. B. (x,y). hypotenuse. r. y (opposite side). A. C. x (adjacent side). Right Triangle Based Definitions of Trigonometric Functions.
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Sec 2.1 Trigonometric Functions of Acute Angles October 1, 2012
Right Triangle w/ Respect to Angle A B (x,y) hypotenuse r y (opposite side) A C x (adjacent side)
Right Triangle Based Definitions of Trigonometric Functions For any acute angle A in standard position,
Right Triangle Based Definitions of Trigonometric Functions For any acute angle A in standard position,
I Do It Find the values of the six trigonometric functions for angle A. 14 19 23 A
We Do It Together Find the values of the six trigonometric functions for angle A. 52 46 A 22
Cofunctions Find the values of the six trigonometric functions for angle A and B. 52 46 A 22
Cofunctions B Conclusions: c a C A b
Reviewing Facts about Right Triangle • The sum of the three angles in any triangle is ____. • Angle B and angle A are ____________ angles. (Since angle C = 90°, the sum of angle A + angle B = 180°- 90° = ____.
Cofunctions Since angles A and B are: complementary &sinA = cosB (A + B = 90°) The functions sine and cosine are called COFUNCTIONS!
Since & sinA = cosB Thus…
Cofunction Identities For any acute angle A, since
Cofunction Identities For any acute angle A, since
Cofunction Identities For any acute angle A, since
I Do It Write the following in terms of its cofunctions.
We Do It Together Write the following in terms of its cofunctions.
You Do It Together Write the following in terms of its cofunctions.
Homework Pg. 68 #7, 9, 11, 13, 15,17, 19, 21
Warm – Up (10/2) Write the following in terms of its cofunctions.
Cofunctions Since angles A and B are: complementary &sinA = cosB (A + B = 90°) The functions sine and cosine are called COFUNCTIONS!
I Do It Find a value of θ satisfying each equation. Assume that all angles involved are acute angles.
We Do It Together Find a value of θ satisfying each equation. Assume that all angles involved are acute angles.
You Do It Together Find a value of θ satisfying each equation. Assume that all angles involved are acute angles.
Comparing Function Values of Special Angles r r A A r A
Conclusion:As A increases, y increases. Since r is fixed, sinA increases. r y r y A A r y A
Conclusion:As A increases, x decreases. Since r is fixed, cosA decreases. r r A A x x r A x
Conclusion:As A increases, y increases and x decreases. Since r is fixed, tanA increases. r y r y A A x x r y A x
I Do It Tell whether each statement is true or false. TRUE
We Do It Together Tell whether each statement is true or false. FALSE
You Do It Together Tell whether each statement is true or false. TRUE
You Do It Together Tell whether each statement is true or false. FALSE
Homework (10/2) Pg. 69 # 23 – 33 odds
Warm – Up (10/3) Tell whether each statement is true or false.
30° 60° Trigonometric Function Values of Special Angles 30°- 60°- 90° Triangle: 30° 1 1 1 x 60° 1
Trigonometric Function Values of 30°-60°-90° Angles For 30° angle: Hypotenuse = Side Opposite = Side Adjacent = 1 30° 60°
Trigonometric Function Values of 30°-60°-90° Angles For 60° angle: Hypotenuse = Side Opposite = Side Adjacent = 1 30° 30° 60°
Trigonometric Function Values of 45°-45°-90° Angles For 45° angle: Hypotenuse = Side Opposite = Side Adjacent = 45° 1 x 45° x
I Do It Give the exact trigonometric function value.
We Do It Together Give the exact trigonometric function value.
We Do It Together A line makes a 30° angle with the x – axis and crosses through the origin. What is the equation of the line?
You Do It Together A line makes a 45° angle with the x – axis and crosses through the origin. What is the equation of the line?