In math, a function is a statement that contains one or more variables that can be calculated to produce one or more answers. Math functions range from the simple to the complex. Evaluating a function at a particular point is one of the most common ways to solve a math function.
Continue ReadingIt is common to be given a function and asked to evaluate it at a certain point. A statement like: "Given the function y = -4x+9, evaluate it at x= -2" simply requires you to use the given value for x (-2) in the function (y = -4x+9). In this example, once an x-value of -2 is plugged into the function, it looks like this: y = -4(-2) + 9. Using simple multiplication and addition, the answer to the function emerges as y = 1. This means that the y-value of the function when x = -2 is 1.
Another way to understand what this means is to think about the graph of the function. The given function is the formula for a straight line, and you have calculated that when x = -2, y = 1. This means that the line of the graph passes through the point (-2, 1), where -2 is the x-value and 1 is the y-value. Evaluating the function for a different value of x and joining the resulting point to (-2, 1) gives a line that can then be extended to show all possible solutions for the function.
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