∵3sin²A+2sin²B=1
∴3sin²A=cos(2B) ①
∵3sin(2A)=2sin(2B)
∴3sinAcosA=sin(2B) ②
①/②,得
tanA=cot(2B)
∵A为锐角,
∴cot(2B)=tanA>0
∴2B也是锐角
∴A+2B=90°
3sin(a)^2+2sin(b)^2=1,3sin(a)=2sin(b),a,b都为锐角,求a+2b的值
1个回答
相关问题
-
已知3sin²a+2sin²b=1,3sin2a﹣2sin2b=0,且a,b都是锐角,求a+2b的值
-
已知a、b为锐角,且满足3sin^2a+2sin^2b=1,3sin2a-2sin2b.求证a+2b=3.14/2
-
a、b∈（0,π/2）,3sin^2 a+2sin^2 b=3sin2a-2sin2b=o,求a+2b的值
-
在三角形ABC中,如果sin2A+sin2B=sin(A+B),且A、B都是锐角,求A+B的值
-
1.已知a、b属于（0,90）,且3sin^a+2sin^b=1,3sin^a-2sin^b=0,求a+2b的值.
-
sin(a+b)=1,则sin(2a+b)+sin(2a+3b)=
-
设A,B为锐角,且sin^2 A+sin^2 B=sin(A+B),求证A+B＝90
-
tan(a+b）=3,tan(a-b)=1/2,求sin2a/sin2b
-
tg(A+B)=3tgA,2sin2B-sin2A=sin(2A+2B)
-
sina=1/3,sin(a+b)=1,求sin(3a+2b)的值