8th grade math vocab
constant of proportionality
The constant ratio between two quantities is also called as constant of proportionality i.e. if x is proportional (directly) to y, then k = . There are times when you will need to find the constant in an equation.
constant of variation
The constant of variation in a direct variation is the constant (unchanged) ratio of two variable quantities. Example 1: If y varies directly as x and y = 15 when x = 24, find x when y = 25. The constant of variation in an indirect variation is the constant (unchanged) product between two variable quantities.
constant rate of change
For straight lines, the rate of change (slope) is constant (always the same). For every one unit that is moved on the x-axis, two units are moved on the y-axis. This is true at any location on the line.
1 : mathematical relationship between two variables that can be expressed by an equation in which one variable is equal to a constant times the other. 2 : an equation or function expressing direct variation
Linear relationships can be expressed in a graphical format where the variable and the constant are connected via a straight line or in a mathematical format where the independent variable is multiplied by the slope coefficient, added by a constant, which determines the dependent variable.
point slope form
Point slope form is the quickest method for finding the equation of line given two points
A measerment of the movement of the y axis
A measurement of the movement of the x axis
In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line. Slope is often denoted by the letter m. The direction of a line is either increasing, decreasing, horizontal or vertical. A line is increasing if it goes up from left to right.
slope intercept form
The slope-intercept form is simply the way of writing the equation of a line so that the slope(steepness) and y-intercept (where the line crosses the vertical y-axis) are immediately apparent. Often, this form is called ' y = mx + b'form.
Standard form is a way of writing down very large or very small numbers easily.
The method of solving "by substitution" works by solving one of the equations (you choose which one) for one of the variables (you choose which one), and then plugging this back into the other equation, "substituting" for the chosen variable and solving for the other.
systems of eqations
A system of equations is a collection of two or more equations with a same set of unknowns. In solving a system of equations, we try to find values for each of the unknowns that will satisfy every equation in the system.
where the graph crosses the x axis
where the graph crosses the y axis