且满足asinB=bcosA 则根号二sinB-cosC的取值范围
√2sinB-cosC=1-cosC-2≤1-cosC≤0 这块怎么算的啊
更正如下B+C=180-A=135B=135-C√2sinB-cosC=√2sin(135-C)-cosC=√2sin(45+C)-cosC=sinC用0<sinC≤1 0<√2sinB-cosC≤1