Isidro L. answered • 07/31/19
AP Calculus AB /Algebra Teacher 20 years Experience.
For this problem you have to be familiar with the unit circle . You can download a copy as pdf of the unit circle from the internet.
1) In the unit circle the x represent the cosine of the function and the y represent the sine of the trigonometric function.
2) Looking at the unit circle I noticed that cos(x) =1, corresponds to 360°. in other words cos (360º) =1, the answer is x=360º or x=2π radians.
3) you can check your answer in your graphing calculator by pressing mode and making sure that your calculator is in degree. Now that you calculator is in degree you can type cos(360) press enter and that answer should be 1. So cos(360) =1.
or you can use the nit circle as I mentioned earlier and look and the x value in the right side of the unit circle
(1,0)= (x, y). So the cosine of some angle is equal to 1, and that angle is 360º.
