This self checking worksheet uses the values 0 to pi for arccos, arccot, and arcsec the values -pi/2 to pi/2 for arctan, arcsin and arccsc. I needed one more review of this type, so I created this one. I already had worksheets 1, 2 and 3, which get progressively harder. This one is easier, so I called this one 1/2. (A little math humor there.) Upon completion, the student will discover the authors to books never written.