cosa=3/5,0_数学解答 - 作业小助手

cosa=3/5,0

人气：350 ℃　时间：2020-04-16 20:07:47

解答

cosa=3/5
0所以sina>0
(sina)^2+(cosa)^2=1
sina=√[1-(cosa)^2]=4/5
cos(a-π/6)
=cosacosπ/6+sinasinπ/6
=(3/5)*(√3/2)+(4/5)(1/2)
=(3√3+4)/10