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