余弦函数的单调性答:0+2kπ]k属于z为单调递减区间,当函数为y=Acos(wx+B)时,(注:w为偶米噶,B为西格玛,都打不来),求单调性,比如求单调递减区间要令t=wx+B,∵y=Acost的单调递减区间为[0+2kπ,π+2kπ]k属于z,∴0+2kπ≤wx+B≤π+2kπ,
高一数学题:正弦函数,余弦函数的性质— 奇偶性,单调性,最值_百度...答:(1)函数f(x)的单调递减区间:pai/2+2kpai<=x-pai/4<=3/2pai+2kpai 区间为[(3/4)pai+2kpai,(7/4)pai+2kpai]k为整数 (2)f(x)在[0,pai],最值在0,3/4π上取得,f(0)=b,f(3/4π)=b+(根号2+1)a a<0,b=3,a=1-根号2 ...