1.求证：[sin^2a+tan(a/2)tana+cos^2]*(sin^2a/2cosa)=tana [sin^2a 是sina指的平方,可能看不太清]2.已知：tan(a/2)=2,求(6sina+cosa)/(3sina-2cosa)的值3.已知：sin^2a+sin2acosa-cos2a=1,a属于(0,π/2),求sina,tana

求证tan^2asin^2a=tan^2a-sin^2a求证tan^2 a 乘 sin^2 a=tan^2 a-sin^2 a 求证 cos^2 a-sin^2 a/1-2sin acos a =1+tan a/1-tan a 求证：tan a/2＝(1-cos)/sin a=sin a/(cos a+1) 求证sin与tan 已知3sinB=sin(2A+B),求证tan(A+B)=2tanA 已知 3sin A = sin (2B +A ),求证 ： tan（A+B)= 2tanB 已知sin(a+β)=1,求证;tan(2a+3β)-tanβ=0 已知3sinβ=sin(2a+β)求证tan(a+β)=2tan a 求证 sin~4a-cos~4a=sin~2a-cos~2a tan~2asin~2a=tan~2a-sin~2a 求证:(tan a*sin a)/(tan a-sin a)=(tan a+sin a)/(tan a*sin a) 已知3sin b=sin(2a+b) 求证tan(a+b)=2tana 求解 已知 sin(a+b)=1/2 ,sin(a_b)=1/3,求证:tan a=5tan b求解:已知 sin(a+b)=1/2 ,sin(a_b)=1/3,求证:tan a=5tan b tan^2a=2tan^2⊙+1求证sin^2⊙=2sin^2a-1 已知(tan^2)a=2(tan^2)B+1,求证：(sin^2)B=2(sin^2)A-1 已知tan^2A=2tan^B+1求证sin^2B=2sin^2A-1救急 已知tan^2a=2tan^2b+1,求证:sin^b=2sin^2a-1 已知tan^2A=2tan^B+1,求证sin^2B=2sin^2A-1 已知sin^2B=2sin^2A-1求证tan^2A=2tan^B+1 已知tan^2 a=2tan^ B +1,求证sin^2 b=sin^2 a -1