高中数学均值定理【急】
\u9ad8\u4e2d\u6570\u5b66\u9898\uff0c\u5747\u503c\u5b9a\u7406\uff0c\u6025\uff01\uff01\uff016\uff0c\u5df2\u77e5x+2y=2\uff0c\u7531\u5747\u503c\u5b9a\u7406\uff1a
3^x+3^2y\u22652\u221a(3^x*3^2y)=2\u221a((3)^(x+2y))=2\u221a3^2=3;
7,y=x+1/x+3(x>0),\u7531\u5747\u503c\u5b9a\u7406\uff1ay=x+1/x+3\u22652\u221ax*1/x+3=5;
8,\u33d2x*\u33d2y=log(x+y)\u2265Log(2\u221a(xy))
9;\u56e0x,y\u2208R+(\u6b63\u5b9e\u6570\uff09\uff0cx+2y\u22652\u221a(x*2y),\u6240\u4ee52\u221a\uff082xy)\u226440,\u221a(2xy)\u226480,xy\u22643200;
10,y=-2x^2+8x=-2(x^2-4x)=-2(x^2-4x+4-4)=-2(x-2)^2+8
\u56e0\u4e3a:-2(x-2)^2\u22640\uff0c\u6240\u4ee5\u5f53-2\uff08x-2\uff09^2=0,\u5373x=2\u65f6\uff0cYmax=8
y>=2\u221ax\u00d71\uff0fx=2 x=1
y\u22652\u221ax²\uff0f3\u00d712\uff0fx²=2\u00d72=4
y\u22652\uff0b2\u221ax\u00d74\uff0fx=6
y=4-\ufe59x\uff0b1\uff0fx\ufe5a\u22644-2\u221ax\u00d71\uff0fx=2
\u6700\u540e\u4e00\u9898\u5e94\u8be5\u662f\u6253\u9519\u4e86 \u5982\u679c\u662f\u6700\u5927\u503c\u5c31\u662f\u6b63\u65e0\u7a77
明显是从AC的中点与B点的距离=16+9/4=73/4开根就是 。
具体分析如下：等值面积就是两个面积相等。底相同，高相同。新的cd=1/2AC,根据勾股定理CD的平方=[(4*4)+(3/2)*(3/2)]
于是得到答案=73/4开根
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