sina:cos(a/2)=4:5,tg(a/4)=?RT

sina:cos(a/2)=4:5,tg(a/4)=?RT 已知 4sinA=1-cosA .求tg(A/2)的值? 已知 4sinA=1-cosA .求tg(A/2)的值(过程!) 已知 4sinA=1-cosA .求tg(A/2)的值 cos a =0.75 求tg a tg a/2化简成sin cos 急!数学题!如果tg(a+b)=2/5,tg(b-派/4)=1/4,那么tg(a+派/4)为? 已知sin(a+kpai)=-2cos(a+kpai)(k属于z)求(4sina-2sina)/(5sina=3sina)1.(4sina-2sina)/(5sina=3sina)2.0.25sin^2 a+0.4cos^2 a在线等,需要过程,有答案了会加分求(4sina-2cosa)/(5cosa+3sina) 之前打错 若sina+cosa/sina-cosa=2,则4sin^2a-3sinacosa-5cos^2a= sin(a+kpai)=-2cos(a+kpai),k属于Z求(4sina-2cosa)/(5cosa+3sina) sin(a+kπ)=2cos[a+(k+1)π].求5cosa+3sina/4sina-2cosa sin(a+kπ)=2cos[a+(k+1)π].求5cosa+3sina/4sina-2cosa 己知[sina+2cos(5兀/2+a)]/[cos(兀-a)-sin(兀-a)]=-1/4求tana的值、求(sina+cosa)平方的值 已知sina+sin^2a=1,求3cos^2a+cos^4a-2sina+1 已知sina=msin(a+2b),m不等于1,求证:tg(a+b)=(1+m)/(1-m)*tgb. 已知[sina(a-π/4)]/cos(π+2a)=根号2,则sina+cosa=? sina+cosa=-3/根号5,且|Sina|>|cos a|,求tan(a/2) cos(a+π/6)=-4/5 sina=?