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30.f(x)=√3sin(2x)+cos(2x)+2=2[(√3/2)sin(2x)+(1/2)cos(2x)]+2=2[sin(2x)cos(π/3)+cos(2x)sin(π/3)]+2=2sin(2x+π/3)+2最小正周期T=2π/2=πsin(2x+π/3)∈[-1,1]，f(x)∈[0,4]31.双曲线:x^2/a^2-y^2/b^2=1椭圆:x^2/5^2+y^2/3^2=1相同焦点，5^2-3^2=c^2=a^2+b^2=16=4^2(c=4)椭圆离心率为e1=4/5，双曲线离心率e2=c/a=4/ae1+e2=2,e2=6/5,a=10/3,a^2=100/9,a^2+b^2=16,b^2=44/9... |
