Exact values & associated angles

1. Exact Values Fo r Higher you need to be able to calculate some trig 
values without a calculator. To help us do this we need to 
 learn the following triangles. ***These are not given in the formula sheet!!! 60o 30o 45o 45o 2 1 1 1 √ 3 √ 2 We use basic Trig (SOHCAHTOA) to find any angle 
above. sin 30 = opp/adj = ½

2. Associated Angles We can also find angles related to Examples Find sin 135o Step 1: Draw the 4 quads and 
plot angle. Step 2:  Use "SATC" from S4  to determine "+" or "-" Step 3: Head towards the x axis 
to get related angle 30, 45 and 60o 135o 180 90 270 The angle is in Quad 2 Sine is +ve in quad 2 So the related angle will be +ve 135o 180 45o so Sin 135  =  + Sin 45  = 1/√2