特殊角的三角函数,1,导入新课,0.9659,0.8121,1.5926,0.9686,0.8071,0.5012,0.9999,3.1022,随堂练习,0.0175,0.9999,0.1736,0.9848,0.3420,0.9397,0.5,0.8660,0.6428,0.7660,0.7071,0.7071,0.7660,0.6428,0.8660,0.5,0.3420,0.9397,0.1736,0.9848,0.0175,0.9999,当锐角逐渐增大时,它的正弦值逐渐增大,它的余弦值逐渐减小.,当090时,0sin1, 0cos1,2.当锐角逐渐增大时,它的正弦值逐渐增大,它的余弦值逐渐减小.,3.当090时,0sin1, 0cos1,1.,课堂小结一,1.,2.,课堂小结二,1.熟练运用计算器计算三角比 2.完成习题2.3的相关习题,