在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的...在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的值.2:若a-b=
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![在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的...在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的值.2:若a-b=](/uploads/image/z/1241366-14-6.jpg?t=%E5%9C%A8%E4%B8%89%E8%A7%92%E5%BD%A2ABC%E4%B8%AD%2CA%2CB%E4%B8%BA%E9%94%90%E8%A7%92%2C%E8%A7%92A%2CB%2CC%E6%89%80%E5%AF%B9%E7%9A%84%E8%BE%B9%E5%88%86%E5%88%AB%E4%B8%BAa%2Cb%2Cc%2C%E4%B8%94sinA%3D%E6%A0%B9%E5%8F%B75%2F5%2CsinB%3D%E6%A0%B9%E5%8F%B710%2F10.1%EF%BC%9A%E6%B1%82A%2BB%E7%9A%84...%E5%9C%A8%E4%B8%89%E8%A7%92%E5%BD%A2ABC%E4%B8%AD%2CA%2CB%E4%B8%BA%E9%94%90%E8%A7%92%2C%E8%A7%92A%2CB%2CC%E6%89%80%E5%AF%B9%E7%9A%84%E8%BE%B9%E5%88%86%E5%88%AB%E4%B8%BAa%2Cb%2Cc%2C%E4%B8%94sinA%3D%E6%A0%B9%E5%8F%B75%2F5%2CsinB%3D%E6%A0%B9%E5%8F%B710%2F10.1%EF%BC%9A%E6%B1%82A%2BB%E7%9A%84%E5%80%BC.2%EF%BC%9A%E8%8B%A5a-b%3D)
在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的...在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的值.2:若a-b=
在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的...
在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的值.2:若a-b=根号2-1,求a,b,c的值
在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的...在三角形ABC中,A,B为锐角,角A,B,C所对的边分别为a,b,c,且sinA=根号5/5,sinB=根号10/10.1:求A+B的值.2:若a-b=
sinA=√5/5,所以cosA=2√5/5;sinB=√10/10,则cosB=3√10/10,cos(A+B)=cosAcosB-sinAsinB=√2/2,A+B=45°,C=135°.a-b=√2-1,又-√2/2=cosC=[a²+b²-c²]/(2ab),少条件啊.
sinA=根号5/5,sinB=根号10/10
sinA/sinB=根号2=a/b
a=根号2b
a-b=根号2-1
b=1,a=根号2
A+B=45 ,余弦得到C
1sinA=根号5/5,A为锐角所以cosA=五分之二倍根号五,同理cosB=十分之三倍根号十
sin(A+B)=sinACOSB+COSASINB=二分之根号二,A+B=45
正弦定理:a/sinA=b/sinB=c/sinB=2R
a-b=2R(sinA-sinB);
所以R=根号10/2;
a,b也就知道了
再根据余弦定理,算出c