函數(shù)y=(33x-23cosx)(5x+70sinx)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，并通過描點法，詳細介紹函數(shù)y=(33x-23cosx)(5x+70sinx)的圖像示意圖畫法步驟。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可以取任意實數(shù)，所以：函數(shù)y=(33x-23cosx)(5x+70sinx)的定義域為：(-∞，+∞)。函數(shù)描點原則：由于三角函數(shù)具有周期性，本題用描點法畫函數(shù)y=(33x-23cosx)(5x+70sinx)的圖像。考慮周期性，本例需畫出在區(qū)間[-4π，4π]上的圖像示意圖，故取點原則為間隔1/4個周期進行取點。函數(shù)特征點圖表：x-4π-3.75π-3.5π-3.25π-3π-2.75π33x-23cosx-437.7-405.0-362.9-320.7-288.0-268.85x+70sinx-62.8-9.415.0-1.6-47.1-92.7y274883807-54445131356524918x-2.5π-2.25π-2π-1.75π-1.5π-1.25π33x-23cosx-259.2-249.5-230.3-197.7-197.7-113.35x+70sinx-109.3-84.8-31.422.046.429.9y28331211587231-4349-9173-3388x-π-0.75π-0.5π-0.25π00.25π33x-23cosx-80.7-61.5-51.8-42.2-239.75x+70sinx-15.7-61.3-77.9-53.4053.4y12673770403522530518x0.5π0.75ππ1.25π1.5π1.75π33x-23cosx51.894.0126.7145.9155.5165.25x+70sinx77.961.315.7-29.9-46.4-22.0y403557621989-4362-7215-3634x2π2.25π2.5π2.75π3π3.25π33x-23cosx184.3217.0259.2301.4334.0353.25x+70sinx31.484.8109.392.747.11.6y578718402283312794015731565x3.53.75π4π33x-23cosx362.9372.5391.75x+70sinx-15.09.462.8y-5444350224599函數(shù)圖像示意圖：y=(33x-23cosx)(5x+70sinx)y (-4π,27488)(-2.5π,28331)(4π,24599)(-3π,13565)(3π,15731)(2π,5787)(-π,1267)(-3.25π,513)x