函數(shù)y=(33x-38cosx)(38x+65sinx)的圖像示意圖主要內(nèi)容：本文根據(jù)三角正弦函數(shù)和余弦函數(shù)的周期性，并通過(guò)描點(diǎn)法，詳細(xì)介紹函數(shù)y=(33x-38cosx)(38x+65sinx)的圖像示意圖畫(huà)法步驟。函數(shù)的定義域：根據(jù)本題涉及的函數(shù)及其特征，為一次函數(shù)和三角函數(shù)和差的乘積，可知自變量x可以取任意實(shí)數(shù)，所以：函數(shù)y=(33x-38cosx)(38x+65sinx)的定義域?yàn)椋?-∞，+∞)。函數(shù)描點(diǎn)原則：由于三角函數(shù)具有周期性，本題用描點(diǎn)法畫(huà)函數(shù)y=(33x-38cosx)(38x+65sinx)的圖像?？紤]周期性，本例需畫(huà)出在區(qū)間[-4π，4π]上的圖像示意圖，故取點(diǎn)原則為間隔1/4個(gè)周期進(jìn)行取點(diǎn)。函數(shù)特征點(diǎn)圖表：x-4π-3.75π-3.5π-3.25π-3π-2.75π33x-38cosx-452.7-415.6-362.9-310.1-273.0-258.238x+65sinx-477.5-401.7-352.8-342.0-358.1-374.3y2161641669471280311060549776196644x-2.5π-2.25π-2π-1.75π-1.5π-1.25π33x-38cosx-259.2-260.1-245.3-208.3-208.3-102.738x+65sinx-363.5-314.6-238.8-163.0-114.1-103.3y942198182758578339532376710609x-π-0.75π-0.5π-0.25π00.25π33x-38cosx-65.7-50.9-51.8-52.8-38-1.038x+65sinx-119.4-135.5-124.7-75.8075.8y78456897645940020-76x0.5π0.75ππ1.25π1.5π1.75π33x-38cosx51.8104.6141.7156.5155.5154.638x+65sinx124.7135.5119.4103.3114.1163.0y64591417316919161661774325200x2π2.25π2.5π2.75π3π3.25π33x-38cosx169.3206.4259.2312.0349.0363.838x+65sinx238.8314.6363.5374.3358.1342.0y404296493394219116782124977124420x3.53.75π4π33x-38cosx362.9361.9376.738x+65sinx352.8401.7477.5y128031145375179874函數(shù)圖像示意圖：y=(33x-38cosx)(38x+65sinx)y (-4π,216164)(4π,179874(3.5π,128031)(3π,124977)(-3.25π,106054)(-3π,97761)(-2.5π,94219)(2π,40429)