cos(A-C)+cosB=1.5 = cos(A-C) - cos(A+C) = 2sinAsinC = 3/2
b^2/ac = (sinB)^2/(sinA·sinC) = (4/3)·(sinB)^2 = 1
sinB = 二分之根三 ,B =60或120
cos(A-C)+cosB=1.5 = cos(A-C) - cos(A+C) = 2sinAsinC = 3/2
b^2/ac = (sinB)^2/(sinA·sinC) = (4/3)·(sinB)^2 = 1
sinB = 二分之根三 ,B =60或120