已知2005x^3=2006y^3=2007z^3,且1/x+1/y+1/z=1,说明3√2005x^2+2006y^2+2007z^2=3√2005+3√2006+3√2007.说明:2005x^3是三次方,3√2005x^2+2006y^2+2007z^2整个式子开3次方.3√2005也是开三次方.

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/07 23:37:40
已知2005x^3=2006y^3=2007z^3,且1/x+1/y+1/z=1,说明3√2005x^2+2006y^2+2007z^2=3√2005+3√2006+3√2007.说明:2005x^3是三次方,3√2005x^2+2006y^2+2007z^2整个式子开3次方.3√2005也是开三次方.

已知2005x^3=2006y^3=2007z^3,且1/x+1/y+1/z=1,说明3√2005x^2+2006y^2+2007z^2=3√2005+3√2006+3√2007.说明:2005x^3是三次方,3√2005x^2+2006y^2+2007z^2整个式子开3次方.3√2005也是开三次方.
已知2005x^3=2006y^3=2007z^3,且1/x+1/y+1/z=1,说明3√2005x^2+2006y^2+2007z^2=3√2005+3√2006+3√2007.
说明:2005x^3是三次方,
3√2005x^2+2006y^2+2007z^2整个式子开3次方.
3√2005也是开三次方.

已知2005x^3=2006y^3=2007z^3,且1/x+1/y+1/z=1,说明3√2005x^2+2006y^2+2007z^2=3√2005+3√2006+3√2007.说明:2005x^3是三次方,3√2005x^2+2006y^2+2007z^2整个式子开3次方.3√2005也是开三次方.
设2005x^3=2006y^3=2007z^3=S^3
则2005=s^3/x^3,2006=s^3/y^3,2007=s^3/z^3.
左边=3√2005x^2+2006y^2+2007z^2=三次根号[(1/x+1/y+1/z)s^3]=s
右边=s/x+s/y+s/z=s(1/x+1/y+1/z)=s
所以原式成立.

啊 ~~~