asinπ/4-bcosπ/4=√2/2(a-b)

问题描述:

asinπ/4-bcosπ/4=√2/2(a-b)
为什么asinπ/4-bcosπ/4=√2/2(a-b)

sin(π/4)=cos(π/4)=√2/2
所以 asinπ/4-bcosπ/4=√2/2(a-b)