Show that #cot (-390°)-4 cos 480# = #2-sqrt3#.?
1 Answer
See the method below.
Explanation:
Recall that
Since all trigonometric functions repeat after 360˚ we can add or subtract 360˚ to the angles without changing anything. Doing this we get
We can write
This can be further simplified as
Consulting the unit circle we find the following:
We can now substitute these values in.
Simplifying we get
Rearranging we get