Weird algebra functions?

Ah, but it does have a variable! The variable just has no say in the rest of the equation.

Try plotting f(x) = -5 on a graph. No matter what point x you plug in, the y value is always -5... That is the equation of a straight line, parallel to the x-axis, running through the y-axis at y = -5.

Recall that the general form of an equation for a straight line is y = mx + b, where (x,y) are the coordinates of any point on the line, m is the slope, and b is the y-intercept. If y = -5, then you can also write it as

y = 0x - 5

As previously described, -5 is the y-intercept, and a slope of 0 makes the line parallel to the x-axis, a well as makes x irrelevant in the determination of y.

Im doing practice problems to help with an exam, and I ran across "f(x)=-5" and Im supposed to solve using functions like "f(2)."

I know how to solve a function, but how can you solve a function with no variable?

THINK...CONSTANT !!

f(x) = - 5

the graph is a horizontal line at y = - 5 [forever]

any value of x has a corresponding y-value of - 5...

that is how to solve !

If f(x) = -5, then f(1) = -5, f(2) = -5, f(1000) = -5.

To say that f(x) = -5 is to say the function f assigns the number -5 to any number x that you input.

Examples?