精品偷拍一区二区三区,亚洲精品永久 码,亚洲综合日韩精品欧美国产,亚洲国产日韩a在线亚洲

  • <center id="usuqs"></center>
  • 
    
  • 求1-cos^6x-sin^6x/1-cos^4x-sin^4x的值,

    求1-cos^6x-sin^6x/1-cos^4x-sin^4x的值,
    數(shù)學(xué)人氣:231 ℃時(shí)間:2020-06-24 08:50:41
    優(yōu)質(zhì)解答
    (1-cos^6x-sin^6x)/(1-cos^4x-sin^4x)
    =[1-(cos^6x+sin^6x)]/[1-(cos^4x-sin^4x)]
    =[1-(cos^2x+sin^2x)(cos^4x-cos^2xsin^2x+sin^4x)]/[1-(cos^2x-sin^2x)(cos^2x+sin^2x)]
    =[1-(cos^4x-cos^2xsin^2x+sin^4x)]/[1-(cos^2x-sin^2x)]
    =[1-(cos^4x+2cos^2xsin^2x+sin^4x-3cos^2xsin^2x)]/[1-cos^2x+sin^2x]
    ={1-[(cos^2x+sin^2x)^2-3cos^2xsin^2x]}/[sin^2x+sin^2x]
    ={1-[1-3cos^2xsin^2x]}/(2sin^2x)
    =(1-1+3cos^2xsin^2x)/(2sin^2x)
    =3cos^2xsin^2x/(2sin^2x)
    =3cos^2x/2看不太懂這么復(fù)雜嗎用平方差和立方差
    我來(lái)回答
    類似推薦
    請(qǐng)使用1024x768 IE6.0或更高版本瀏覽器瀏覽本站點(diǎn),以保證最佳閱讀效果。本頁(yè)提供作業(yè)小助手,一起搜作業(yè)以及作業(yè)好幫手最新版!
    版權(quán)所有 CopyRight © 2012-2024 作業(yè)小助手 All Rights Reserved. 手機(jī)版