- A circular arc of 90°; one fourth of the circumference of a circle.
- Any of the four areas into which a plane is divided by the reference axes in a Cartesian coordinate system, designated first, second, third, and fourth, counting counterclockwise from the area in which both coordinates are positive.
quadratic equation 二次方程式An equation that employs the variable x having the general form ax2 + bx + c = 0, where a, b, and c are constants and a does not equal zero; that is, the variable is squared but raised to no higher power.
quadrilateral 四边形A polygon having four sides.
quadrillion 十的十五次方A cardinal number represented in the U.S. by 1 followed by 15 zeros, and in Great Britain by 1 followed by 24 zeros.
qualitative data 定性数据Data that are non-numeric, such as colors, images and descriptions. Qualitative data are harder to analyze than quantitative data, which are numeric quantities.
quantitative data 定量数据Numeric data. Quantitative data are much easier to analyze than qualitative data, which are descriptive and open to interpretation.
quantity 数量An entity having a magnitude that may be denoted by a numerical expression.
quarter 四等份之一, 15分钟, quarter
- One of four equal parts.
- One fourth of an hour; 15 minutes.
- One fourth of a year; three months.
quartile 四分位数Any of the groups that result when a frequency distribution is divided into four groups of equal size.
quotient 商The result of division. The number obtained by dividing one quantity by another. In 45 ÷ 3 = 15, 15 is the quotient.