根号下tanX+lg(1-tanX)的定义域

显示全部楼层 · 2010-4-22 13:34:10

确保根号下大于等于0, lg大于零1-tanx>0(-pi/2+2kpi, pi/4+2kpi)(-无穷 , 1)x=0 tanx=0 lg1-tanx=0x>0 tanx > 0 lg1-tanx > 0x 0 所以值小于0范围为:[2kpi, pi/4+2kpi)

千问 · 2010-4-22 13:34:10

1、定义域是Rx系数是1所以T=2π/1=2π2、五点法即sin里取0，π/2，π，3π/2，π则x-π/3=0,x=π/3,sin(x-π/3)=0x-π/3=π/2,x=5π/6,sin(x-π/3)=1x-π/3=π,x=4π/3,sin(x-π/3)=0x-π/3=3π/2,x=11π/6,sin(x-π/3)=-1x-π/3=2π,x=7π/3,sin(x-π/3)=0所以过(π/3,0)(5π/6,2),(4π/3,0),(11π/6,-2),(7π/3,0)自己瞄一下即可