n^4-3n^2+9
=n^4+6n^2+9-9n^2
=(n^2+3)^2-(3n)^2
=(n^2-3n+3)(n^2+3n+3)
当n为大于等于3的自然数时
n^2-3n+3=(n-2)(n-1)+1>1
n^2+3n+3>1
即n^4-3n^2+9可以写成两个大于1的自然数的积的形式
所以n^4-3n^2+9是合数
试判断当n为大于等于3的自然数时,代数式n^4-3n^2+9表示质数还是合数
试判断当n为大于等于3的自然数时,代数式n^4-3n^2+9表示质数还是合数
如上
如上
其他人气:193 ℃时间:2019-08-21 06:17:58
优质解答
我来回答
类似推荐
猜你喜欢
- 1一个真分数的分子与分母是两个连续自然数,如果在分母上加2,这个分数值就是七分之六,原来的真分数是
- 2人教语文八年级下册第一单元第一课 野藤先生 的课后生字词拼音和解释、在线等、
- 3英语翻译
- 4Amy doesn't want to go shopping because she is very busy 对because she is very busy提问
- 5what is your fanther ?保持句意不变 _____ _____does his father do?
- 6Jack always works hard and he sets a good e( ) for us.
- 7已知函数f(x)=ax^2+bx+1,a,b为实数,x属于R.(1)若f(x)=0,有一个根为-1,且函数f(x)的值域为【0,∞】求
- 8直接引语变间接引语:1、Tom said'what do you want,Lucy'?2、He said 'I haven't seen her today.'
- 9She never worry because we care of her.这个句子里哪一点错了
- 10他不顾医生的忠告用英语怎么写