y is a variable just like x is a variable. So what's a variable, right? It's a symbol we use when we don't know how many we have of something or when the number of them can change. y + 5 means we add 5 to whatever we decide y stands for. It could be any number, so we're just holding its place with the variable.
A dependent variable represents a quantity whose value depends on how the independent variable is manipulated. y is often the variable used to represent the dependent variable in an equation.
Actually “twice y” means that the value would be twice the value of y. Twice means two times of a quantity or variable. It means that “twice y” can be expressed as two times of y. That is, \[2\times y=2y\].
A linear equation in two variables can be described as a linear relationship between x and y, that is, two variables in which the value of one of them (usually y) depends on the value of the other one (usually x). In this case, x is the independent variable, and y depends on it, so y is called the dependent variable.
The slope and y-intercept values indicate characteristics of the relationship between the two variables x and y. The slope indicates the rate of change in y per unit change in x. The y-intercept indicates the y-value when the x-value is 0.
Linear function - has the form y = mx + b where the rate of change is constant m. Graph is a straight line. Exponential function - has the form y = a^x, where the rate of change is NOT constant and is different for different values of x.
Incidentally, the funny upside-down y is a greek letter called "lamda".
Symbol. ∥ (geometry) Parallel lines. indicates that line AB is parallel to line CD.
y = mx + b is the slope-intercept form of the equation of a straight line. In the equation y = mx + b, m is the slope of the line and b is the intercept. x and y represent the distance of the line from the x-axis and y-axis, respectively. The value of b is equal to y when x = 0, and m shows how steep the line is.
This notation is probably the most common when dealing with functions with a single variable. If, instead of a function, we have an equation like y = f ( x ) y=f(x) y=f(x)y, equals, f, left parenthesis, x, right parenthesis, we can also write y′ to represent the derivative.
In single variable calculus, a function is typically graphed with the horizontal axis representing the independent variable and the vertical axis representing the dependent variable. In this function, y is the dependent variable and x is the independent variable.
The variable x is called the independent variable (also sometimes called the argument of the function), and the variable y is called dependent variable (also sometimes called the image of the function.)
The estimated or predicted values in a regression or other predictive model are termed the y-hat values. “Y” because y is the outcome or dependent variable in the model equation, and a “hat” symbol (circumflex) placed over the variable name is the statistical designation of an estimated value.
Letter. The twenty-fifth letter of the English alphabet, called wye and written in the Latin script. Used for the Greek letter Υ (Y, “upsilon”).
Lambda, the 11th letter of the Greek alphabet (λ), is used as both a symbol and a concept in various fields of science, mathematics and computing. Although originally used as a symbol for wavelength in mathematical equations, developers and engineers now use lambda in computer programming and cloud computing.
The yen and yuan sign, ¥, is a currency sign used for the Japanese yen and the Chinese yuan currencies when writing in Latin scripts. This monetary symbol resembles a capital letter Y with a single or double horizontal stroke.
Exponential functions are of the form y=bˣ, where b>0, and not equal to 1. The constant b is called the base.
In an exponential function, the independent variable, or x-value, is the exponent, while the base is a constant. For example, y = 2x would be an exponential function.
Definition: The y-intercept is the point where a graph crosses the y-axis. In other words, it is the value of y when x=0.