2.6.1: Key Terms
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Key Terms
- correlation coefficient
- a value, r, between –1 and 1 that indicates the degree of linear correlation of variables, or how closely a regression line fits a data set.
- decreasing linear function
- a function with a negative slope: If f(x)=mx+b,thenm<0.
- extrapolation
- predicting a value outside the domain and range of the data
- horizontal line
- a line defined by f(x)=b, where b is a real number. The slope of a horizontal line is 0.
- increasing linear function
- a function with a positive slope: If f(x)=mx+b,thenm>0.
- interpolation
- predicting a value inside the domain and range of the data
- least squares regression
- a statistical technique for fitting a line to data in a way that minimizes the differences between the line and data values
- linear function
- a function with a constant rate of change that is a polynomial of degree 1, and whose graph is a straight line
- model breakdown
- when a model no longer applies after a certain point
- parallel lines
- two or more lines with the same slope
- perpendicular lines
- two lines that intersect at right angles and have slopes that are negative reciprocals of each other
- point-slope form
- the equation for a line that represents a linear function of the form y−y1=m(x−x1)
- slope
- the ratio of the change in output values to the change in input values; a measure of the steepness of a line
- slope-intercept form
- the equation for a line that represents a linear function in the form f(x)=mx+b
- vertical line
- a line defined by x=a, where a is a real number. The slope of a vertical line is undefined.
- x-intercept
- the point on the graph of a linear function when the output value is 0; the point at which the graph crosses the horizontal axis
- y-intercept
- the value of a function when the input value is zero; also known as initial value