220,∴k12设直线BM:y2pk2x2p,与y2px联立得k2y22py4p21k20
2
由24p216p2k21k20,得12k220,∴k2故直线AM:y2p2x2p,直线BM:y2p从而不难求得Ap0,B2p0,C0p,
12
1x2p,2
∴SBOCp,SABM3p2,∴BOC的面积与四边形AOCM的面积之比为
2
p21(为定值)223pp2
21(1)解:fxgx证明如下:
9
f设hxfxgx3ex9x1,∵hx3ex2x9为增函数,
x2
∴可设hx00,∵h060,h13e70,∴x001当xx0时,hx0;当xx0时,hx0∴hxmi
hx03e0x029x01,
x
又3e02x090,∴3e02x09,
xx
∴hxmi
2x09x029x01x0211x010x01x010∵x001,∴x01x0100,∴hxmi
0,fxgx(2)证明:设xxex4x5fxx3exx24x5x0,令xx2e20,得x1l
2,x22,
x
则x在0l
2上单调递增,在l
22上单调递减,在2上单调递增
29e22,设t2l
2t2,
m2∵m3em3m500m2,m2∴m3em4m5m0m2,即mm0m2
当0at时,x02a,则xe4x5fxa
xx当tam时,xmi
a,∵xe4x5fxa,∴aa,∴tam
当ma2或a2时,不合题意从而0am
10
f22解:(1)∵
y23t,∴x,即y3x2,yx3x
又t0,∴3
230,∴x2或x0,x
∴曲线M的普通方程为y3x2(x2或x0)∵4cos,∴24cos,∴x2y24x,即曲线C的直角坐标方程为
x24xy20
(2)由
y3x2x4xy0
22
得x4x30,
2
∴x11(舍去),x23,则交点的直角坐标为33,极坐标为2323解:(1)由fx2,得
6
x11x4x4或或,22x2022x82
解得0x5,故不等式fx2的解集为05
22xx1(2)fxx4x13r