若tan(π－α)＝2，则2sin(3π＋α)·cos＋sin·sin(π－α)的值为________．
式子cos2＋cos2＝________.
若P(－4,3)是角α终边上一点，则的值为________．
已知sinα是方程5x2－7x－6＝0的根，α是第三象限角，则＝________.
化简＝________.
sin21°＋sin22°＋sin23°＋…＋sin288°＋sin289°＋sin290°的值为________．
＋sin
·sin(π－α)的值为________．
＋cos2
＝________.
的值为________．
＝________.
＝________.