求|x-3| |x 4|的最小值,并说明此时有理数x的取值范围.
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x^2-3x+1=0x^2+1=3x两边同除以xx+1/x=3x^2+1/x^2=(x+1/x)^2-2=9-2=7x^4+1/x^4=(x^2+1/x^2)^2-2=49-2=47
x^2/x^4+x^2+1=1/x^2+x^2+1x+1/x=3(x+1/x)^2=3^2=9x^2+1/x^2+2=9x^2+1/x^2=7则x^2+1/x^2+1=8即x^2/x^4+x^2+1=
f′(x)=5x4+20x3+15x2=5x2(x+3)(x+1),当f′(x)=0得x=0,或x=-1,或x=-3,∵0∈[-1,4],-1∈[-1,4],-3∉[-1,4]列表:又f(0)=0,f
y=-2/3x²+4/3x+2=-2/3(x²-2x-3)=-2/3(x-3)(x+1)二次函数与X轴的交点坐标为(3,0)、(-1,0)y=-2/3(x²-2x-3)的
x²+1=-3x两边平方x^4+2x²+1=9x²x^4+1=7x²两边平方x^8+2x^4+1=49x^4x^8+1=47x^4两边除以x^4x^4+1/x^
令t=x^2+1>=1则x^2=t-1代入函数得:f=[(t-1)^2+3(t-1)+6]/t=[t^2-2t+1+3t-3+6]/t=[t^2+t+4]/t=t+4/t+1t+4/t>=2√(t*4
x^2+x+1=0,x不等于0方程两边÷x,x+1+1/x=0x+1/x=-1(x+1/x)^2=1x^2+1/x^2+2=1x^2+1/x^2=-1X^4+1/X^4=(X^2+1/X^2)^2-2
经过编写程序计算,最优解为:x1=0x2=300x3=1200x4=900x5=500x6=0时,x1+2*x2+3*x3+4*x4+5*x5+9*x6的最小值为:10300再问:我算的是10500再
x^2-3x+1=0x^2+1=3xx+1/x=3(x+1/x)^2=9x^2+1/x^2+2=9x^2+1/x^2=7(x^2+1/x^2)^2=49x^4+1/x^4+2=49x^4+1/x^4=
f’(x)=4x3-4/x由复合函数易知此函数为增函数易知f’(-1)=0所以在-e
(1)x-1/x=-2(2)x2+1/x2=1/2(3)x4+1/x4=1/4再问:能告诉我过程吗?再答:(1)已知x2+2x-1=0则x²-1=2x等式两边同时除以x不等于0的数得:x-1
x2/x4+x2+1上下除以x^2=1/(x^2+1+1/x^2)=1/[(x+1/x)^2-1]=1/(9-1)=1/8
设(x0,x04+x0-2)为y=f(x)图象上任意一点,它到l的距离d=|x40+x0−2−x0+4|2=x40+22≥22=2,故距离最小距离为2上述等号当且仅当x0=0时取得,故相应点坐标为(0
y=4*2^x-3*(2^x)²x∈[-1,0]令2^x=t,则t∈[1/2,1]y=-3t²+4t,t∈[1/2,1]画图,函数y=-3t²+4t的图象是开口向下,对称
f'(x)=5x^4+20x^3+15x^2=05x^2(x^2+4x+3)=05x^2(x+1)(x+3)=0x1=0,x2=-1,x3=-3-10故函数在[-1,4]上是单调增函数,故最大值=f(
x4是指4x还是指x^4?
x平方-3x+1=0二边同除以xx-3+1/x=0x+1/x=3x^2+1/x^2=(x+1/x)^2-2=3^2-2=7x^4+1/x^4=(x^2+1/x^2)^2-2=7^2-2=47
f(x)=x4-2x2?5