单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,2.3 用计算器求锐角三角比,第二章,1,特殊角的三角函数,角,三角比,30,45,60,sin,cos,tan,1,2,1,2,2,2,3,3,2,1,2,3,2,2,3,3,导入新课,2,3,4,5,0.9659,0.8121,1.5926,0.9686,0.8071,0.5012,0.9999,3.1022,随堂练习,6,0.0175,0.9999,0.1736,0.9848,0.3420,0.9397,0.5,0.8660,0.6428,0.7660,0.7071,0.7071,0.7660,0.6428,0.8660,0.5,0.3420,0.9397,0.1736,0.9848,0.0175,0.9999,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0,90时，0sin,1,0cos,1,7,2.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0,90时，0sin,1,0cos,1,1.,课堂小结一,8,9,10,11,1.,2.,课堂小结二,12,