sin^2b=tan^2b/1+tan^2b

因为 tan^2b=sin^2b/1-sin^2b 所以sin^2b=tan^2b/1+ tan^2b 为什么sin^2b=tan^2b/1+ tan^2b? sin^2b=tan^2b/1+tan^2b 若tan^2 a=2tan^2 b+1,则cos2a+sin^ b=? 已知sin(A+B)=3/5,sin(A-B)=1/5,证明：tan A=2tan B. 已知 tan a =1 3sin(a+b)=sin(2a+b) ,求 tan(a+b) 的 值. tan a +tan b=-4 ,tan a tan b=-7,求sin^2(a+b)+4sin(a+b)-cos ^2 (a+b)的值. 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=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 已知tan(a-r)/tana+sin^2b/sin^2a=1 ,求证tan^2b=tana*tanr.. 已知tan²a=2tan²b+1,求证sin²b=2sin²a-1 已知tan²a=2tan²B+1,求证sin²B+1=2sin²a 已知tan²a=2tan²b+1,求证sin²b+1=2sin²a tan a=3tan(a+b),b=pai/6求sin(2a+b)