- 初二数学题题在附件里因为有上标,所以用图片发题目请高手答题时也如
- 题在附件里
因为有上标,所以用发题目
请高手答题时也如此,以便分辨指数与系数、常数
- (3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)
=1/2(3-1)(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)
=1/2(3^2-1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)
=1/2(3^4-1)(3^4+1)(3^8+1)(3^16+1)
=1/2(3^32-1)
(x+1)(x-2)(x-3)(x-6)
=[(x+1)(x-6),(x-3)(x-2)]
=[(x^2-5x)-6,(x^2-5x)+6]
=x^4-10x^3+25x^2-36
x^2+y^2+6y+10
=x^2+y^2+6y+9+1
=x^2+(y+3)^2+1
因为x^2+(y+3)^2+1恒大于0，
所以原式恒大于0