2012年高考全国卷数学题:已知ω>0,函数f(x)=sin(ωx+π/4)在(π/2,π)上单
w>0上
当x属于(π/2,π)时,wx+π/4属于(wπ/2+π/4,wπ+π/4)
函数f(x)=sin(ωx+π/4)在(π/2,π)上单调递减
故:2kπ+π/2《wπ/2+π/4
wπ+π/4《2kπ+3π/2
得到4k+1/2《w《2k+5/4
故4k+1/2《2k+5/4
k《3/8
k=0
得到1/2《w《5/4
若满意请采纳!!谢谢
w>0上
当x属于(π/2,π)时,wx+π/4属于(wπ/2+π/4,wπ+π/4)
函数f(x)=sin(ωx+π/4)在(π/2,π)上单调递减
故:2kπ+π/2《wπ/2+π/4
wπ+π/4《2kπ+3π/2
得到4k+1/2《w《2k+5/4
故4k+1/2《2k+5/4
k《3/8
k=0
得到1/2《w《5/4
若满意请采纳!!谢谢