12. 下面是来自美国教材上的一道题:
The quadratic equation$2x^{2}-8x+1=0$has roots α and β.
(a)Without solving the equation, find the value of
(ⅰ)$α+β;$
(ⅱ)$αβ.$
(b)Another quadratic equation$x^{2}+px+q=0(p,q∈Z)$has roots$\frac {2}{α}$and$\frac {2}{β}.$
Find the value of p and the value of q.
意思是:已知方程$2x^{2}-8x+1=0$有两个根α和β.
(1)不解方程,求:①$α+β$;②$αβ$.
(2)另一方程$x^{2}+px+q=0(p,q$为整数)有两个根$\frac {2}{α}$和$\frac {2}{β}$,求$p$和$q$的值.
The quadratic equation$2x^{2}-8x+1=0$has roots α and β.
(a)Without solving the equation, find the value of
(ⅰ)$α+β;$
(ⅱ)$αβ.$
(b)Another quadratic equation$x^{2}+px+q=0(p,q∈Z)$has roots$\frac {2}{α}$and$\frac {2}{β}.$
Find the value of p and the value of q.
意思是:已知方程$2x^{2}-8x+1=0$有两个根α和β.
(1)不解方程,求:①$α+β$;②$αβ$.
(2)另一方程$x^{2}+px+q=0(p,q$为整数)有两个根$\frac {2}{α}$和$\frac {2}{β}$,求$p$和$q$的值.
答案
(1) ① 4 ② $\frac{1}{2}$ (2) $p = -16$,$q = 8$。
13. 是否存在这样一个矩形,它的周长和面积的数值都等于6? 若存在,请求出相邻两边的比;若不存在,请说明理由.
答案
不存在,理由略。
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