Hey guys,

I have a problem with my TI-89 titanium. I'm currently doing some trig functions and the answer to some of the equations are

looking quite strange to me. For instance, if i plug in:

cos(x)=0.516,xin solve,

I get this:

2·@n9·π+1,02862...Rather than a number. Does anyone know what the problem is?

Any help much appreciated!