sketch the graph of each of the trigonometric functions for $\displaystyle 0 <\theta<2\pi$
$\displaystyle y=1-2sin\theta$
When θ = 0, y = 1.
When θ = 30, y = 0.
When θ = 90 y = -1.
When θ = 150, y = 0.
when θ = 180, y = 1.
When θ = 270 y = 3.
When θ = 330, y = 2
When θ = 360, y = 1.