命题P:对X属于[1,2],不等式X^2>或=k恒成立.命题Q:关于的X方程X^2-X+k=0有实数根.如果“非P”为假,“P且Q”为假,求的取值范围.ps:我做了,想对下答案.我的答案是k<或=1\4,P得到k<或=1。Q得到k<
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命题P:对X属于[1,2],不等式X^2>或=k恒成立.命题Q:关于的X方程X^2-X+k=0有实数根.如果“非P”为假,“P且Q”为假,求的取值范围.ps:我做了,想对下答案.我的答案是k<或=1\4,P得到k<或=1。Q得到k<
命题P:对X属于[1,2],不等式X^2>或=k恒成立.命题Q:关于的X方程X^2-X+k=0有实数根.
如果“非P”为假,“P且Q”为假,求的取值范围.ps:我做了,想对下答案.
我的答案是k<或=1\4,P得到k<或=1。Q得到k<或=1/4.
命题P:对X属于[1,2],不等式X^2>或=k恒成立.命题Q:关于的X方程X^2-X+k=0有实数根.如果“非P”为假,“P且Q”为假,求的取值范围.ps:我做了,想对下答案.我的答案是k<或=1\4,P得到k<或=1。Q得到k<
k的范围是大于四分之一,小于等于一.不知道你的答案是多少.
过程:非p为假,那么p是真命题,x^2>或=k恒成立就必须k<或=x^2的最小值,因为x^2是递增函数,所以最小值是1..那么K<或=1;p且q为假,前面p是真,那么q 是假命题,对应的这个方程有实根不成立,那么就得到
b^2-4ac<0,也就是1-4k<0,k>1/4..
所以答案因该是:1/4
1/4
around 5 am , a Guangdong Brand A written meat transport vehicles designed truck is heading for the airport expressway to the airport ,chaussures louboutin, suddenly a brand of trailer E F rushing dia...
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around 5 am , a Guangdong Brand A written meat transport vehicles designed truck is heading for the airport expressway to the airport ,chaussures louboutin, suddenly a brand of trailer E F rushing diagonally from the left , once the truck 's front was damaged . People fail to figure out how much the middle of Geli with 20 cm of cement barrier in the middle there are many trees and flowers ,Chaussures Louboutin Pas Cher, why head-on collision ?
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8:49 Guangzhou traffic police on the microblogging real-time traffic news release ,Christian Louboutin pas cher, said the airport by high-speed car accident Pincha road trailer and the impact of the existing airport high-speed greater traffic flow , traffic is slow . 20 minutes after the scene of the accident is expected to be cleared .
across the buffer zone was knocked down four trees
airport highway this morning, slow traffic
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不对,由P得k<或=1,由Q得k>1/4 所以答案为1/4