✔ 最佳答案
about Inequalities
find the maximum and minimum values of the following and find
he corresponding values of x，where 0°≦x≦ 360
1. 2^(Cosx)
Sol
－1<=Cosx<=1
2^(－-1)<=2^(Cosx)<=2^1
1/2<=2^(Cosx)<=2
2. 6/(3－Sinx)
Sol
－1<=Sinx<=1
－1<=－Sinx<=1
2<=3－Sinx<=4
1/2>=1/(3－Sinx)>=1/4
3>=6/(3－Sinx)>=3/2
2011-03-23 23:15:59 補充：
1. 2^(Cosx)
Sol
－1<=Cosx<=1
2^(－1)<=2^(Cosx)<=2^1
1/2<=2^(Cosx)<=2
when min Cosx=－1=>x=180度
when max Cosx=1 => x=0 or 360度
2. 6/(3－Sinx)
Sol
－1<=Sinx<=1
－1<=－Sinx<=1
2<=3－Sinx<=4
1/2>=1/(3－Sinx)>=1/4
3>=6/(3－Sinx)>=3/2
when min Sinx=1=>x=90度
when max Sinx=-1 =>x=270度
