2-sinx≠π+kπ/2(k=0,±1,±2...)
2-sinx≠π/2
sinx≠2-π/2
x≠arcsin(2-π/2)+2kπ(k=0,±1,±2...)
x≠-arcsin(2-π/2)+(2k+1)π(k=0,±1,±2...)
定义域是
{x|x≠arcsin(2-π/2)+2kπ且x≠-arcsin(2-π/2)+(2k+1)π(k=0,±1,±2...)}
-1≤sinx≤1
1≤2-sinx≤3
y≤tan3或y≥tan1
值域就是
{y|y≤tan3或y≥tan1}