在GRE數(shù)學(xué)考試中,一般都假定以下信息為真:
●All numbers used are real numbers;
●All figures lie on a plane unless otherwise indicated;
●All angle measures are positive;
●All lines shown as straight are straight. On the computer-based test, lines that appear“jagged" can also be assumed to be straight (lines can look somewhat jagged on the computer screen):
●Figures are intended to provide useful information for answering the questions. However,except where a figure is accompanied by a“Note" stating that the figure is drawn tO scale, solve the problem using your knowledge of mathematics, not by visual measurement or estimation.
細(xì)心的讀者會(huì)發(fā)現(xiàn),上述假設(shè)實(shí)際上就是ETS 出題原則,即:
●所有的數(shù)都是實(shí)數(shù);
●除非GRE數(shù)學(xué)題目中專門指出假設(shè)所有圖形都在同一個(gè)平面內(nèi);
●所有的角的測量值都是正數(shù);
●所有顯示為直線的線均可當(dāng)作直線來處理(在機(jī)試中,因?yàn)殡娔X顯示器的原因,直線可能會(huì)看起來呈“鋸齒狀”);
●伴隨問題的圖形將為解題提供有用的信息。但是,只有在GRE數(shù)學(xué)的問題中指出本圖形是按比例畫出(drawn to scale)時(shí),才可以用目測或估計(jì)而得到的信息去解題。否則,只能運(yùn)用你的數(shù)學(xué)知識(shí)去回答問題。這一解題原則可以簡稱為“只能讀圖,不能度量”的原則。