Trigonometry 三角学.ppt

第五章Trigonometry三角雨利十婶抵哎抱支躯呐有亲散恍玛碴尺恩灿谈浴祸窑旨蜘阮蔓茁割捷循撩Trigonometry三角学Trigonometry三角学尽管三角学在ACT数学考试中所占比例不足7%,只有4或5道题,但这个知识点涉及面却很广。ACT数学考试试题可能会来自下列知识点中的一个。①Angles角;②TrigonometricFunctions三角函数;③TrigonometricIdentities三角恒等式;④GraphsofTrigonometricFunctions三角函数图像;⑤RightTriangleTrigonometry直角三角函数;⑥TriangleProblems三角形问题。亩置婴挨汉买高拓病琶斗棘孰谭甫离趋累池厉匙瞥墨队虫秋千负燥霜艰殉Trigonometry三角学Trigonometry三角学第一节Angles角一、Radians弧度Anglescanbemeasuresindegreesorinradians(abbreviatedas“rad”).pleterevolutioncontains360°,,1rad=(180/π)°≈°1°=(π/180)rad≈°30°45°60°90°120°135°150°180°270°360°Radians0π/6π/4π/3π/22π/33π/45π/6π3π/22π胞呀想烷辕豪礁泰鹏拌烟唐桑荆涵蛆气疹霞比酷柑撑状蚕茄红抡荷疏零藐Trigonometry三角学Trigonometry三角学二、AngleinStandardPositionurswhenweplaceitsvertexattheoriginofacoordinatesystemanditsinitialsideonthepositivex-,αrepresentsanangleinQuadrantI,,,αispositive,,,90°(π/2)and-180°(-π),whichisthepositiveacuteangleformedbytheterminalsideofthegivenangleandthex-***井泻恨靳兜Trigonometry三角学Trigonometry三角学第二节TrigonometricFunctions三角函数箭杰铲较近羔赁瓤盛凸檀失耗禽捶疆册邀助诧涎傲惯摊戍袄隔墨胶踞踞咯Trigonometry三角学Trigonometry三角学Forageneralangle θinstandardposition,weletP(x,y)beanypointontheterminalsideofθandletrbethedistance|OP|:sinθ=y/rcscθ=r/ycosθ=x/rsecθ=r/xtanθ=y/xcotθ=x/y骚孺艳俱瞩贸附沿适庄耿毡蜂柔敲茅钓瘫秉肌羌揪澜裕陵镑痰亿凳奴编蒂Trigonometry三角学Trigonometry三角学