Problema Solution
If an angle lies in the quadrant IV what can be the value of cos of that angle
Answer provided by our tutors
let x = the angle
the angle lies in the quadrant IV means
270 <= x <= 360
since the function cos is ascending in the interval [270, 360]
cos 270 <= cos x <= cos 360
cos 270 = 0
cos 360 = 1
thus we have
0 <= cos x <= 1