文档介绍：三角函数 解三角形知识点总结例题剖析
三角函数
ll5、半径为的圆的圆心角所对弧的长为，则角的弧度数的绝对值是( ,,,,rr
,,,6、弧度制与角度制的换算公式:，， 1,2360,,180
lCSCrl,，27、若扇形的圆心角为，半径为，弧长为，周长为，面积为，则，，,,为弧度制lr,,r，，
112(8、设是一个任意大小的角，的终边上任意一点的坐标是，它与原点的距离是,,,xy,Slrr,,,，，22
yyx22，则sin,,，cos,,，( tan0,,,xrrxy,，,0，，，，rrx
9、三角函数在各象限的符号:第一象限全为正，第二象限正弦为正，
第三象限正切为正，第四象限余弦为正(11、角三角函数的基本关系:
222222;1sincos1,,，,sin1cos,cos1sin,,,,,,,,，，，，
sin,sin,,,,(12、函数的诱导公式: 2tan,,,sintancos,cos，，,,,,,,cos,tan,,,
1sin2sink,,,，,，cos2cosk,,,，,，tan2tankk,,,，,,,( ，，，，，，，，，，2sinsin,,,，,,coscos,,,，,,tantan,,,，,，，( ，，，，，，，，
3sinsin,,,,,coscos,,,,tantan,,,,,，，( ，，，，，，，，
4sinsin,,,,,coscos,,,,,,tantan,,,,,,，，( ，，，，，，，，
口诀:函数名称不变，符号看象限(
,,,,,,,,,,,,，(，( 5sincoscossin6sincoscossin,,,,，,，,,,,,,,,,,，，，，,,,,,,,,2222,,,,,,,,
口诀:正弦与余弦互换，符号看象限(
,yx,，sin,yx,，sin,13、?的图象上所有点向左(右)平移个单位长度，得到函数的图象;再将函数的图象，，，，
1yx,，sin,,yx,，sin,,上所有点的横坐标伸长(缩短)到原来的倍(纵坐标不变)，得到函数的图象;再将函数，，，，,
,yx,,，sin,,的图象上所有点的纵坐标伸长(缩短)到原来的倍(横坐标不变)，得到函数的图象( ，，
yx,,，,,,sin0,0,,,14、函数的性质: ，，，，
2,1,,,,,,f,,x，,?振幅:;?周期:;?频率:;?相位:;?初相:( ,2,,
15、正弦函数、余弦函数和正切函数的图象与性质:
pipe and the metal structure installation part main including Yunnan province tengchong County yongxing River primary and secondary hydropower station in the of pressure pipe and the power station metal structure, which level power station pressure pipe total about 562t (containing annex); II level power station pressure pipe about 733 t (containing annex); level power station metal structure about t, containing discharge Gate 2 hole, rushed sand Gate 1 hole, water mouth work door and the stopped dirt gate the 1 hole, Qian pool work door and the stopped dirt gate the 1 hole; Secondary power station metal junction at about t, containing sand Gate 1 hole, water inlet water gate and trash the 1 hole; their auxiliary hoist equipment and electrical equipment. Concrete pressure pipe, gate, trash and hoisting device project property list 1-1~1-3. Table 1-1 the main characteristics of the penstock number item p