How do I force matlab to return multiple solutions for a periodic function?

For example: cosd(1) and cosd(359) are both equal to 0.9998, however, matlab will only return "1" for the equation acosd(0.9998). How do you get matlab to return 359 for acosd(0.9998)

Answer 1

[Azzi Abdelmalek]

You can find yourself all the other solutions, Matlab gets the one in the intervall [0 180], in your case the solution is 1. The other solutions are:

-1+k*180 
1+k*180