求证:sin a(1+tan a)+cos a(1+1/tan a)=1/sin a+1/cos a

求证:(tan a*sin a)/(tan a-sin a)=(tan a+sin a)/(tan a*sin a) 求证:sin a(1+tan a)+cos a(1+1/tan a)=1/sin a+1/cos 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) 已知sin(a+β)=1,求证;tan(2a+3β)-tanβ=0 求证恒等式：（tan a+sec a-1)/(tan a -sec a+1)=（1+sin a）/cos a 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 已知tan^2 a=2tan^ B +1,求证sin^2 b=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tan²a=2tan²b+1,求证sin²b=2sin²a-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 tan^2a=2tan^2⊙+1求证sin^2⊙=2sin^2a-1 已知tan²a=2tan²B+1,求证sin²B+1=2sin²a 已知tan²a=2tan²B+1,求证sin²+2sin²a-1 已知tan²a=2tan²b+1,求证sin²b+1=2sin²a