已知a=2012²+2013²/2011²+2014²,b=2013²+2014²/2012²+2015²,c=2014²+2015²/2013²+2016²则下列不等式正确的是A、a>b>c B、b>c>a C、c>a>b D、c>b>a
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/21 06:44:48
![已知a=2012²+2013²/2011²+2014²,b=2013²+2014²/2012²+2015²,c=2014²+2015²/2013²+2016²则下列不等式正确的是A、a>b>c B、b>c>a C、c>a>b D、c>b>a](/uploads/image/z/609150-30-0.jpg?t=%E5%B7%B2%E7%9F%A5a%3D2012%26%23178%3B%2B2013%26%23178%3B%2F2011%26%23178%3B%2B2014%26%23178%3B%2Cb%3D2013%26%23178%3B%2B2014%26%23178%3B%2F2012%26%23178%3B%2B2015%26%23178%3B%2Cc%3D2014%26%23178%3B%2B2015%26%23178%3B%2F2013%26%23178%3B%2B2016%26%23178%3B%E5%88%99%E4%B8%8B%E5%88%97%E4%B8%8D%E7%AD%89%E5%BC%8F%E6%AD%A3%E7%A1%AE%E7%9A%84%E6%98%AFA%E3%80%81a%EF%BC%9Eb%EF%BC%9Ec+B%E3%80%81b%EF%BC%9Ec%EF%BC%9Ea+C%E3%80%81c%EF%BC%9Ea%EF%BC%9Eb+D%E3%80%81c%EF%BC%9Eb%EF%BC%9Ea)
已知a=2012²+2013²/2011²+2014²,b=2013²+2014²/2012²+2015²,c=2014²+2015²/2013²+2016²则下列不等式正确的是A、a>b>c B、b>c>a C、c>a>b D、c>b>a
已知a=2012²+2013²/2011²+2014²,
b=2013²+2014²/2012²+2015²,c=2014²+2015²/2013²+2016²
则下列不等式正确的是
A、a>b>c B、b>c>a C、c>a>b D、c>b>a
已知a=2012²+2013²/2011²+2014²,b=2013²+2014²/2012²+2015²,c=2014²+2015²/2013²+2016²则下列不等式正确的是A、a>b>c B、b>c>a C、c>a>b D、c>b>a
设f(x)=[(x+1)^2+(x+2)^2]/[x^2+(x+3)^2]=1-4/(2x^2+6x+9)
当x>0时,2x^2+6x+9递增,4/(2x^2+6x+9)递减,1-4/(2x^2+6x+9)递增.
所以,C>b>a,选D.
D
选D
设f(n)=[(n+1)²+(n+2)²]/[n²+(n+3)²]=[2n²+6n+5]/[2n²+6n+9]=1-[4/(2n²+6n+9)],显然f(n)是递增的,则a=f(2011),b=f(2012),c=f(2013),则a
a=2012²+2013²/2011²+2014²
=(2*2012²+2*2012+1)/(2*2012²+2*2012+5)
=1-4/(2*2012²+2*2012+5)
b=1-4/(2*2013²+2*2013+5)
c=1-4/(2*2014²+2*2014+5)
所以a选D