A picture of a function tells you in a moment what a formula hides. In this course we read and draw the graphs of the common functions, we meet the modulus and the greatest integer function, and we learn how to move, stretch and flip a graph. We also learn to see even, odd, increasing and decreasing functions in a picture.
4 lessons, about 1 h 40 min4 simulations16 problems8 practice questionsPython in every lesson
The graph of a function f is the set of points (x, f(x)). We draw it from a table of values and we read domain, range, zeros and the value at a point from it. The six standard graphs are , , , , and . The graph of is a parabola with its vertex at .
The modulus |x| is the distance of x from zero. The signum gives the sign of x. The greatest integer [x] is the largest integer not more than x, and the fractional part is x − [x], which always lies in [0, 1). A function defined by different rules on different parts of its domain is a piecewise function.
Adding a number outside f moves the graph up or down. Changing x inside f moves or squeezes it sideways, and the effect is the opposite of what you may expect. A factor outside stretches the graph up or down. A minus sign outside flips it in the x axis, and a minus sign inside flips it in the y axis.
A function is even if f(−x) = f(x) for every x, and then its graph is symmetric about the y axis. It is odd if f(−x) = −f(x), and then its graph is symmetric about the origin. A function is increasing on an interval if a larger x always gives a larger f(x), and decreasing if a larger x gives a smaller f(x). A function is periodic with period T if f(x + T) = f(x).
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With Standard, you also open 4 more problems and 1 Python lab. Everything you have used here stays free, always.