3sin α 4cos α化简
来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 13:34:32
cos2a=cos^2a-sin^2asin²α-cos²α=-cos(2α)4sinα*cosα=2sin(2α)4sinα*cosα/sin²α-cos²α
齐次式:两侧同时除cos2α,得4tan2α-tanα-3=0,可解tanα=1或tanα=-?
cosα+cosβ=3/5sinα+sinβ=4/5两边平方cos²α+2cosαcosβ+cos²β=9/25sin²α+2sinαsinβ+sin²β=16
cos(π/6+α)=sin(π/3-α),sin(π/4+α)=cos(π/4-α)所以,原式=sin(π/4-α)cos(π/3-α)-sin(π/3-α)cos(π/4-α)=sin(π/4-α
2sin^2α-cos^α+sinα*cosα-6sinα+3cosα=0(2sinα-cosα)(sinα+cosα)-3(2sinα-cosα)=0(2sinα-cosα)(sinα+cosα-3
∵4sinα−2cosα5cosα+3sinα=4tanα−25+3tanα=10,∴tanα=-2.故答案为:-2
是tanα(cosα-sinα)+[sinα(sinα+tanα)/(1+cosα)]吧?先看sinα(sinα+tanα)/(1+cosα),分子为sinα(sinαcosα/cosα+sinα/c
sinα+cosβ=3/4,cosα+sinβ=-5/4(sinα+cosβ)^2=9/16(cosα+sinβ)^2=25/16上两式相加2+2sin(α+β)=34/16sin(α+β)=1/16
分子(1+sinα+cosα)(sinα/2-cosα/2)=[2(cosα/2)^2+2sinα/2*cosα/2](sinα/2-cosα/2)=2cosα/2(sinα/2+cosα/2)(si
1.(1)这是齐次式只要分子分母同时除以cosα就转变成只有tanα的式子(2)先把2写成2(sinα平方+cosα平方)再把分母1改写成sinα平方+cosα平方再分子分母同时除以cosα平方2.(
sina=-2cosatana=-2sin²a-3sinacosa+1=(sin²a-3sinacosa+sin²a+cos²a)/(sin²a+co
sin^6α+cos^6α+3sin^2α*cos^2α=(sin^2α+cos^2α)(sin^4α-sin^2α*cos^2α+cos^4α)+3sin^2α*cos^2α=sin^4α+2sin
sinα+sinβ=3/5,则(sinα+sinβ)^2=9/25,即(sinα)^2+(sinβ)^2+2sinαsinβ=9/25,同理cosα+cosβ=4/5,则(cosα+cosβ)^2=1
因为cosα=1.5sinα,所以原式=0.5/2.5+2.5/0.5=1/5+5=5.2
sinα+sinβ=3/5,则(sinα+sinβ)^2=9/25,即(sinα)^2+(sinβ)^2+2sinαsinβ=9/25,同理cosα+cosβ=4/5,则(cosα+cosβ)^2=1
设含α的直角三角形边长为a,b,csinα=a/ccosα=b/c(a+b)/c=4/3c=3*(a+b)/4c^2=9/16*(a+b)^2a^2+b^2=c^2结合上面得7*(a^2+b^2)=1
1sin²α+cosαcos(π/3+α)-sin²(π/6-α)=sin²α+cosα(cosπ/3cosα-sinπ/3sina)-(sinπ/6cosα-cosπ/
原式=sin(α-π)/cos(π-α)×sinα/sin(α-π)×cos(-α)/sin(-α)=sin[-(π-α)]/(-cosα)×sinα/(-sinα)×cosα/sinα=(-sinα
由4sinα−2cosα5cosα+3sinα=611得,4tanα−25tanα+3=611,即7tanα=20,解得tanα=207,故答案为:207.
切化弦tanα(cosα-sinα)+sinα(sinα+tanα)/1+cosα.=sinα(cosα-sinα)/cosα+sinα(sinα+sinα/cosα)/(1+cosα)=sinα(c