Reference+Angles

A reference angle is used to determine the value of an angle that is not an acute angle. __//**Def: **//__ The ACUTE angle fromed by the TERMINAL SIDE of the given angle and the X-AXIS. *May apear in all 4 quadrents. Finding Refenence Angles: =Q2 =180-(~) OR (Pie)-(~) Q3 =(~)-180 OR (~)-Pie= =Q4 =360-(~) OR 2Pie-(~) //__ Example: __// Find the value of sin(225 degrees) Since 225 is in quadrant three we subtract 180 from the angle. 225-180=45 Next we find the sin of 45. The sin of 45= sqrt2/2. Finally, it needs to be determined if the value is positive or negative. Since sin is only positive in quadrants one and two, and 225 lies in quadrant 3, the final answer is negative. //__ Links: __// [|Reference Angles] [|Practice Quiz] [|Video] [|Power Point]=
 * __//Reference Angles// __**
 * Q1** =(~)