初中奧數(shù)代數(shù)恒等式證明練習(xí)題2016

字號(hào):

1. 求證: ①(a+b+c)2+(a+b-c)2-(a-b-c)2-(a-b-c)2=8ab
    ②(x+y)4+x4+y4=2(x2+xy+y2)2 ③(x-2y)x3-(y-2x)y3=(x+y)(x-y)3
    ④3 n+2+5 n+2―3 n―5 n=24(5 n+3 n-1) ⑤a5n+a n+1=(a3 n-a2 n+1)(a2 n+a n+1)
    2.己知:a2+b2=2ab 求證:a=b
    3.己知:a+b+c=0
    求證:①a3+a2c+b2c+b3=abc ②a4+b4+c4=2a2b2+2b2c2+2c2a2
    4.己知:a2=a+1   求證:a5=5a+3
    5.己知:x+y-z=0    求證: x3+8y3=z3-6xyz
    6.己知:a2+b2+c2=ab+ac+bc 求證:a=b=c
    7.己知:a∶b=b∶c      求證:(a+b+c)2+a2+b2+c2=2(a+b+c)(a+c)
    8.己知:abc≠0,ab+bc=2ac   求證:
    9.己知:求證:x+y+z=0
    10.求證:(2x-3)(2x+1)(x2-1)+1是一個(gè)完全平方式
    11己知:ax3+bx2+cx+d能被x2+p整除 求證:ad=bc