Functions Are Your Friend
Functions are machines. Plug the independent variable into the machine and it spits out the dependent variable.
Sample ProblemIf y = f(x) = x + 1, then as x gets larger (moves right), y gets la...
Graphing and Visualizing Limits
It's super helpful to plug numbers into the function and see the output. It's even more helpful to graph the results. Try to draw or imagine how a function actually looks. Is it really hip to be x2...
Piecewise Functions and Limits
Now we'll shake things up a bit by taking limits with piecewise-defined functions. Here's an example: What is ?If we draw the graph of this function, we see that it looks like the line y = x + 1...
One-Sided Limits
Becky has been planning her Florida vacay for months. The only thing left on her to-do list is to find a new bathing suit. She's cruising the web to find the perfect one. Eventually, she gives up o...
Limits via Tables
There's more than one way to approach (pun absolutely intended) limit problems. We've already looked at graphs and equations. Another way to estimate the limit of a function is to use a calculator...
Limits via Algebra
Most of the time, it's more precise (and a lot faster) to find limits using algebra. When finding a limit of the form , where f(x) is just one nice algebraic expression, the first thing to do...
Vertical Asymptotes
Now we'll check out one of the rock stars of the limit world:To the right, to the right, to the right, to the rightWe'll look at this limit one side at a time. First we'll look at the limit as x ap...
Finding Vertical Asymptotes
Vertical asymptotes most frequently show up in rational functions. When a rational function, f(x), has a non-zero constant in the numerator and an expression with a variable in the denominator, the...
Vertical Asymptotes vs. Holes
Both vertical asymptotes and holes are places that the curve can't quite seem to touch. Holes occur at places where the limit of the function exists, but the function itself does not. For rational...
Limits of Functions at Infinity
When we find the limit of a function f(x) as x goes to infinity, we're answering the question "What value is f(x) approaching as x gets bigger and bigger and bigger...?''A rockin' example of this i...
Finding Horizontal/ Slant/ Curvilinear Asymptotes
Sometimes when a function has a horizontal asymptote, we can see what it should be. Sample ProblemLet f(x) = 4-x. Then as x approaches ∞ the function f approaches 0; there's a horizontal asymptot...
How to Draw Rational Functions from Scratch
We now have enough tools to draw some complicated functions from scratch. Now we know how graphing calculators do it, and why they require the energy of four triple-A's.When drawing a rational func...
Power Functions vs. Polynomials
In the world of horse races, power functions like 2x will always grow faster than plain old polynomials, no matter how high the degree of the polynomial. By "grow faster'' we mean that if we go f...
Polynomials vs. Logarithmic Functions
Who wins when we compare polynomials and logarithmic functions? Look at a picture.Eventually, after not too long, the polynomial will pull ahead of the logarithmic function. This makes sense, becau...
The Basic Properties
Basic Property 1If c is a real number, then Think of this as taking the limit of the constant function f(x) = c. No matter what we plug in for x, we get c as the output. If we made a tablexf(x)x1cx...
Adding and Subtracting Limits
Limits can be added and subtracted, but only when those limits exist.Adding and Subtracting Property 1If a is a real number and both and exist, thenIn words, as long as the limits that are added b...
Multiplying and Dividing Limits
Multiplication PropertyAs long as both and exist,In words, the limit of a product is the product of the limits, as long as the limits involved exist.Here's a few more examples of this:Assume Then...
Powers and Roots of Limits
Limits are pretty powerful. They're kind of the big idea of calculus. Throughout calculus we'll see that no matter what we're doing, there's a limit or two lurking somewhere.The purpose of this rea...