若sin(3π-2)=根号2sin(2π+β),根号3cos(-α)=-根号2cos(π+β)0
问题描述:
若sin(3π-2)=根号2sin(2π+β),根号3cos(-α)=-根号2cos(π+β)
0
答
sin(3π-a)=根号2sin(2π+β),根号3cos(-α)=-根号2cos(π+β)∴sina=√2sinβ ①√3cosa=√2cosβ ②①²+②²sin²a+3cos²a=2=2sin²a+2cos²a∴ sin²a=cos²a∴ tana=1或-1(1...