For each equation, find two solutions 0 ≤ x < 2π, which make the equation true. No calculator should be necessary. Homework Help ✎
cos x = −
tan x =
sin x = 0
cos x =
In which quadrants is cosine negative? Sketch a unit circle with right triangles with 30° angles at the origin in the second and third quadrants. What are the circular angles?
x = 120° and 240°
Now convert the angles into radians.
See part (a).
If sin(x) = 0, x = 0.
x = 0
Remember the side ratios of 45° right triangles.