tutorial

y The angle α is 30◦ in the example (π/6 in radians). The sine of α, which is the height of the red line, is 1 sin α =...

0 downloads 19 Views 25KB Size
y The angle α is 30◦ in the example (π/6 in radians). The sine of α, which is the height of the red line, is

1

sin α = 1/2.

1 2

tan α =

sin α α −1

cos α

− 21 − 12

sin α cos α x

1

By the Theorem of Pythagoras we have cos2 α + sin2 α = 1. Thus the length of the blue line, which is the cosine of α, must be p √ cos α = 1 − 1/4 = 12 3. This shows that tan α, which is the height of the orange line, is

−1 tan α =

√ sin α = 1/ 3. cos α