Teaching Trigonometry Cosine Functions - Fun Math Help - Game Tips: - Press the 't' key to see a graph that demonstrates the following example.     The cosine of angle A can be written as cos A and     cos A equals the ratio (x/r) = (3)/(5) when point D is (x,y) = (3,4) and r=AD=5.     With angle A in standard position at the origin, the cosine ratio of A is (x coordinate)/(radius) = (3)/(5).     The radius r=5 can be calculated from point D(3,4) using 32 + 42 = r2. - Press the 'y' key to restart the game. - When angle A is in standard position at the graph's origin (0,0) then cos A equals (x/r).     Since r is the hypotenuse of a right triangle, r can be found from point D(x,y) using x2 + y2 = r2 .     Consequently, cos A can also be described as (adjacent side)/(hypotenuse). - The small square symbol at B indicates AB is perpendicular to BD forming a right angle. - It may take a minute to load the game at dial-up speeds. - The game can be played using the mouse by itself or using the keyboard by itself. - If the game doesn't respond to keyboard input, click inside the game area to reset the game's focus. - Adjust the game's speed by pressing the + or - key repeatedly. More SliderMath   Copyright © All Rights Reserved.
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