A fun part of math is just messing around with various functions. Here you can find some things you can play around with.

Differentiate!

Differentiate a function of your choosing. See all the steps shown.

Graph!

Plot a function of your choosing. Use sliders to control other variables.

Explore Trig Functions!

Play with the relationships between the unit circle, the trig functions, and their graphs.

Hear doppler shift!

Move around a sound-emitting object and an observer to hear doppler shift.

Move trains around!

Slide trains on their tracks, and watch how they move together.

Fifths! Octaves!

Twelve fifths is almost seven octaves—and you can hear this fact.

The method of Euler!

You can plot slope fields! You can see Euler's method in action!

Riemann sums!

Estimate the (signed) area under a curve using a Riemann sum.