3.=___________________.
2.的符是___________(填正或负).
1.的值是__________________.
14.已知则=________;
,则=___________.
13.若角的终边经过P(4)(a)则
12.设,=___;=____.
11.已知,且,则=_____.
10.=____;=___;=______.
9.已知=,则=_______.
8.已知=,且是第二象限角,=_______.