z1=-1+2i
z2=cosa+isina
z1*z2的实部等于 -cosa-2sina=0
tana=-1/2
tan2a=2tana/[1-tan^2(a)]= - 4/3已知函数f(x)=2sinxcosx+2cos^2x1)求函数f(x)的单调递增区间2)将函数y=f(x)图像向右平移π/4个单位后,得到函数y=g(x)的图像,求方程g(x)=1的解f(x)=sin2x+(1+cos2x)=sin2x+cos2x+1=√2sin(2x+π/4)+1由-π/2+2kπ≤2x+π/4≤π/2+2kπ得:-3π/8+kπ≤x≤π/8+kπ,所以原函数的单调增区间为:【-3π/8+kπ,π/8+kπ,】2)g(x)=f(-π/4)=√2sin[2(x-π/4)+π/4]+1=√2sin(2x-π/4)+1即g(x)=√2sin(2x-π/4)+1方程g(x)=1==>√2sin(2x-π/4)=02x-π/4=kπx = π/8+kπ/2社关于x的不等式x(x-a-1)<0(a∈R)的解集为M,不等式(x+1)/(x-3)≤0的解集为N1)当a=1时,求集合M2)若M≦N,求实数a的取值范围1)a=1M=(0,2)N=[-1,3)2) 因为M是N的子集,i)当M是空集时,(a+1)^2≤0;==>a=-1ii)当M不是空集时,根据根的分布M中的两根在【-1,3)中,<==>{f(-1)>0 {f(3)>0 {Δ>0 {-1<(a+1)/2<3.............................................................................................................................................{a+2>0{6-3a>0{a+1≠0{-3
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