設a,b為實數,若|２x+ａ|≤ b之解為-3< x< 5 則(a，b)=?
回答 (2)
2016-07-26 11:07 pm
設a，b為實數，若|２x+ａ|≤ b之解為-3<= x<=5 則(a，b)=?
Sol
－3<=x<=5
－6<=2x<=10
－6－2<=2x-2<=8
｜2x－2｜<=8
a=－2，b=8
Sol
－3<=x<=5
－6<=2x<=10
－6－2<=2x-2<=8
｜2x－2｜<=8
a=－2，b=8
2016-07-26 4:35 pm
x>a+b x<(a+2b+1)/2 所以:a+b=3 (a+2b+1)/2=5 解得:a=-3,b=6 b-a=9
收錄日期: 2021-04-30 21:40:07
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160726081538AAorzlf