sin(4x)=0.8在0≤x≤2π的最大最小值我翻译的不好sin(4x)=0.8findthesmallestsolution,thelargestsolutionandthenumberofsolutionsforxintheinterval0≤x≤2π.4x可以求出来的呀。0.235.27选谁哎，大

Question

sin(4 x) = 0.8 在 0 ≤ x ≤ 2π 的最大最小值
我翻译的不好
sin(4 x) = 0.8 find the smallest solution,the largest solution and the number of solutions for x in the interval 0 ≤ x ≤ 2π.
4x可以求出来的呀。0.23
5.27
选谁哎，大家赶紧在写下求出5.我就选谁吧，不好意思了

Answer 1

sin(4 x) = 0.8,4x=kπ+(-1)^k*arcsin0.8,
x=(1/4)[kπ+(-1)^k*arcsin0.8],k∈Z,
0 ≤ x ≤ 2π ,
K=7时x取最大值（1/4）(7π-arcsin0.8)≈5.265963339弧度,
k=0时x取最小值（1/4）arcsin0.8.