f(x)=(cos^2x-sin^2x)/2，g(x)=1/2sin2x-1/4

显示全部楼层 · 2013-4-12 22:40:33

f(x)=(1/2)cos2x
g(x)=1/2 sin2x-(1/4)g(x)向左平移π/4个单位得到(1/2)sin2(x+π/4)=(1/2)cos2x再向上平移(1/4)个单位得到f(x)的图像 2h(x) = (1/2)cos2x - (1/2)sin2x + (1/4)
=（根号2/2）cos(2x - π/4) + (1/4)最小值 = -（根号2/2）+ (1/4)2x -π/4 = 2kπ+πx = kπ + 5π/8...

千问 · 2013-4-12 22:40:33

1.fx=1/4(cos?0?5x）—3/4（sin?0?5x）=1/4（cos?0?5x—sin?0?5x—2sin?0?5x)=1/4(cos2x+cos2x-1)=1/2cos2x-1/4T=2π/2=π2...

千问 · 2013-4-12 22:40:33

f(x) = (1/2)(cos?0?5x - sin?0?5x) = (1/2)cos2xg(x) = (1/2)sin2x - 1/4 1、先将g(x)左移(π/2)，再上移(1/4)个单位，可得到g(x + π/2) + 1/4 = (1/2)sin(2x + π/2) - 1/4 + 1/4 =...

千问 · 2013-4-12 22:40:33

向左派/4向下1/4单位－根2/2＋1/4，此时X＝（k＋3/8）派...