 Given that and find the value of the cos θ

 Memorize it!  Quiz 1 st week of 2 nd semester ◦ 8 minute time limit ◦ All or nothing ◦ 20 points  There are a lot of patterns  We will go over all of the patterns before the quiz

Section 4.3

 A right triangle has a 90˚ angle and two acute angles a = length of side opposite of θ b = length of side adjacent to θ c = length of the hypotenuse A B C θ

SOH-CAH-TOA

 Find the value of each of the trigonometric functions of θ. 3 4 c A B C θ

5 12 c A B C θ

 Pythagorean triples are integer side lengths of a right triangle      And many more  And any multiple of any of them (such as )

DegreesRadianssincostan 30˚ 45˚ 60˚

 Page 461 #1-19 odd  No calculator

 In Exercises 1-8, use the Pythagorean Theorem to find the length of the missing side of each right triangle. Then, find the value of each of the six trigonometric functions of θ A B C θ 1) 3) A B C θ 10 5) 26 A B C θ

 Find the value of each of the trigonometric functions of θ. a A B C θ

 Clear everything off of your desk except a pencil and eraser.  5 minute time limit  All or nothing  Must be turned in by the end of 5 minutes  Do NOT begin until instructed to do so.  Any talking while any quiz is out will result in a zero.

 The value of a trig function of an angle is equal to the value of the cofunction of the complement of the angle  If θ is in radians, replace 90˚ with

 Find a cofunction with the same value as the given function.

 All scientific and graphing calculators should have buttons for sin, cos, and tan.  Most do not have csc, sec, and cot.  Make sure that your calculator is set to the correct angle measure (degrees or radians)  TI-83: Press [MODE] and make sure the correct one of “Radian” or “Degree” is highlighted

 The angle formed by a horizontal line and the line of sight to an object that is above the horizontal line is the angle of elevation.  The angle formed by a horizontal line and the line of sight to an object that is below the horizontal line is the angle of depression. angle of depression

 Sighting the top of a building, a surveyor measured the angle of elevation to be 24˚. The transit is 5 feet above the ground and 250 feet from the building. Find the building’s height (to the nearest foot).

 At a certain time of day, the angle of elevation of the sun is 39˚. A tree casts a shadow 37 feet long. Find the tree’s height (to the nearest foot).

 Page 462 #21-33 odd, odd  Calculator required

 In Exercises 21-28, find a cofunction with the same value as the given expression.

 At a certain time of day, the angle of elevation of the sun is 59˚. A tree casts a shadow 24 feet long. Find the tree’s height (to the nearest foot).

 Clear everything off of your desk except a pencil and eraser.  5 minute time limit  All or nothing  Must be turned in by the end of 5 minutes  Do NOT begin until instructed to do so.  Any talking while any quiz is out will result in a zero.

 Clear everything off of your desk except a pencil and eraser.  5 minute time limit

 If, then  “Theta equals the inverse sine of x”  Other inverse trig functions follow the same format  TI-83: [2nd] [sin]

 The Washington Monument is 555 feet high. If you stand ¼ mile away (1320 feet), and look at the top, what is the angle of elevation (to the nearest degree)?

 A telephone pole is 55 feet tall. A guy wire 80 feet long is attached from the ground to the top of the pole. Find the angle between the wire and the pole to the nearest degree.

 Page 462 #35-42 ALL

 In Exercises 35-38, use a calculator to find the value of the acute angle θ to the nearest degree.  In Exercises 39-42, use a calculator to find the value of the acute angle θ in radians, rounded to three decimal places.