# How to learn graph plots of math functions?

I really don't know how to we say that a log function would look like this or polynomial function would look like this. I know that if I have like $X + Y = c$, I can draw straight line by taking values of $X$ and evaluating $Y$.

How to I learn graph plots for other math function (log, exponential, sine, cos etc.) or polynomials of degree $n$?

-
Calculus + Memorization. If you know a handful of graphs like $y=\ln(x)$, $y=e^x$, $y=\sin(x)$, lines, and parabolas and also use $f'(x)$ to tell when the function is increasing or decreasing and $f''(x)$ to tell if it's concave up or down you can sketch graphs of a lot of things. – Bill Cook Oct 30 '11 at 22:00
you can know how a graph of a function looks, by drawing it using a computer program (graphic calculator). you can use this one for example: javaboutique.internet.com/PGC – Max Oct 30 '11 at 22:02
peda.com/grafeq – pedja Oct 31 '11 at 7:50

Assuming you understand the convinsion y=f(x)=sin(x) for example and what this means, you can choose values for x and compute the corresponding y values then plot the (x,y) pairs on a chart. The more close the x values are, the better your plot would be.

The above is the simple way. You can try to get more sophisticated and calculate the function max. and min values as well as where the function intersects with x and y axis to make sure your sample x values pass through the critical points that gives this function its distinct looks.

You can also use a calculator or a web page that would help you visualize the plot. Here are some links for you: