ppcq.net
当前位置:首页 >> 化简 1 sinA%CosA >>

化简 1 sinA%CosA

tana=sina/cosa 所以 tana(cosa-sina)+sina(sina+tana)/(1+cosa)=(sina/cosa)*cosa-(sina/cosa)*sina+sina(sina+sina/cosa)/(1+cosa)=sina-(sina)^2/cosa+(sina)^2*(1+1/cosa)/(1+cosa)=sina-(sina)^2/cosa+(sina)^2*[(1+cosa)/cosa]/(1+cosa)=sina-(sina)^2/cosa+(sina)^2/cosa=sina

(1-sina)/(cosa)=[cos(a/2)-sin(a/2)]/[cos(a/2)-sin(a/2)]=[cos(a/2)-sin(a/2)]/[cos(a/2)+sin(a/2)]=[1-tan(a/2)]/[1+tan(a/2)]=tan(π/4-a/2)

原式=[sin(a/2)+cos(a/2)-2sin(a/2)cos(a/2)]/[cos(a/2)-sin(a/2)]=[cos(a/2)-sin(a/2)]/[cos(a/2)+sin(a/2)][cos(a/2)-sin(a/2)]=[cos(a/2)-sin(a/2)]/[cos(a/2)+sin(a/2)]分子分母

由倍角公式:sina=2sin(a/2)cos(a/2),cosa=2cos(a/2)-1,得:1+cosa=2cos(a/2)所以,原式=2sin(a/2)cos(a/2)/2cos(a/2)=sin(a/2)/cos(a/2)=tan(a/2)

(1+sina-cosa)/(1+sina+cosa)=[2sin(a/2)+2sin(a/2)cos(a/2)]/[2cos(a/2)+2sin(a/2)cos(a/2)]=2sin(a/2)[sin(a/2)+cos(a/2)]/{2cos(a/2)[cos(a/2)+sin(a/2)]}=tan(a/2)

[(1/sina)+(cosa/sina)](1-cosa)=[(1+cosa)/(sina)](1-cosa)=[(1+cosa)(1-cosa)]/(sina)=[1-cos^2(a)]/(sina)={1-[(1+cos2a)/2]}/(sina)={[1-cos2a]/2}/(sina)={sin^2(a)}/(sina)=sina

cosa根号下1-sina/1+sina 分子分母同时乘以 1-sina分子=(1-sina)^2 分母=(1+sina)(1-sina)=1-sin^2acosa根号下1-sina/1+sina =cosa根号下[(1-sina)^2/cos^2a]=cosa*(1-sina)/|cosa|cosa>0 =1-sinacosa<0 =-1+sina

1+cosa=2cos^2(a/2)sina/1+cosa=2sina/2cosa/2除以2cos^2(a/2)=sin(a/2)/cos(a/2)=tan(a/2)

1),f(a)=(1-sina cosa)/(1-sina-cosa) (1-sina-cosa)/(1-sina cosa) =(-2sina/2cosa/2 2cos^2a/2)/(-2sina/2cosa/2 2sin^2a/2) (-2sina/2cosa/2 2sin^2a/2)/(-2sina/2cosa/2 2cos^2a/2) =2cosa/2(-sina/2 cosa/2)/2sina/2(-cosa/2 sina/2) 2sina/2(-cosa/2 sina/2

你没有()我理解是:(1-sina+cosa)/(1-sina-cosa)+(1-sina-cosa)/(1-sina+cosa)首先通分=(1-sina+cosa-sina+sin^2a-sin2a+cosa+cos^2a+1-sina-cosa-sina+sin^2a+sin2a-cosa+cos^2a)/(1-sina-cosa)(1-sina+cosa)化简=(2-4sina+2sin^2a+2cos^2a)/[(1-sina)+cosa][(1-sina)-cosa]继续=2(1-2sina+sin^2a+cos^2a)/(1-2sina+sin^2a+cos^2a)最后=2

相关文档
网站首页 | 网站地图
All rights reserved Powered by www.ppcq.net
copyright ©right 2010-2021。
内容来自网络,如有侵犯请联系客服。zhit325@qq.com