问一个数学问题36X
36X-6Y-26=6√37c(a+b)+46 X=2+cosa Y=sina 怎么从36X-6Y-26到6√37cos(a+b)+46 ?
36X-6Y-26=6√37cos(a+b)+46 X=2+cosa Y=sina 怎么从36X-6Y-26到6√37cos(a+b)+46 ? 已知:X=2+cosa Y=sina 所以:36X-6Y-26=36*(2+cosa)-6sina-26=72+36cosa-6sina-26 =36cosa-6sina+46 =√[36^2+6^2]*{(36/√[36^2+6^2])*cosa-(6/√[36^2+6^2])*sina}+46 =6√37*[(6/√37)cosa-(1/√37)sina]+46 =6√37cos(a+b)+46 其中:tanb=(1/√37)/(6/√37)=1/6