OK...let's look at the first one....notice that it's a 45 degree reference angle in the 2nd quadrant. Now, let's ask ourselves....where else is the cosine negative??...yup...in the 3rd quadrant
So this angle is a 45 degree reference angle in the 3rd quadrant, i.e., 225 degrees.
As for the second one, it's a little trickier......the tangent is positive in the 1st quadrant and in the 3rd quadrant, because, in the 3rd quadrant, both x and y are negative. So this angle is a 30 degree reference angle in quadrant 3....... i.e., 210 degrees.
Cosecant is the reciprocal of the sine....not the inverse!! If the sine is defined as y/r, then the csc is just r/y.
Remember that the basic functions return angle values. The inverse functions return the angles themselves.
As for dealing with negative angles.......let me know what you're specifically having trouble with and I'll see what I can do.
I hope I've answered what you've asked....