三角形ABC的三个内角ABC岁对的边为abc,asinAsinB+bcosA的平方=根2a,求b/a;若c方=b方+根3倍的a方,求B
问题描述:
三角形ABC的三个内角ABC岁对的边为abc,asinAsinB+bcosA的平方=根2a,求b/a;若c方=b方+根3倍的a方,求B
答
asinAsinB+bcos²A=√2a,sin²AsinB+sinBcos²A=√2sinA,sin²AsinB+sinB-sin²AsinB=√2sinA,sinB=√2sinA,sinB/sinA=√2,则sinB/sinA=b/a=√2;c²=b²+√3a²,则:c²...