Here are the functions that will graph a heart in a window with an x-max is 10, x-min is -10, y-min is -7, y-max is 7). To input the forward slash use the divide key and to input the inequality signs, press 2nd Math. To use this as a learning opportunity, reflect on how one might graph a circle and a line and how I used these to make a heart. Also, in the curly brackets, I have restricted the domain of the semi-circles and the lines. Think about what you know about domain restrictions and how this is working here. To see the effect of the domain restrictions, try viewing the graph without the domain restrictions.

**Math 30-1** students, ask yourself how I used transformations of a circle to make the first four functions. Look below to understand better how to graph a circle.

**All students**: compare the Pythagorean Theorem to the functions that graph a circle. A semi-circle with radius 3 can be graphed with y=sqrt(9-x^2) which comes from 3^2=x^2 + y^2. Check out some youtube videos about how to graph a circle (a set of points equidistant from a given point.

**More for All**: can you graph an arrow through this heart using y=mx+b? Happy Valentines, everyone.

**Challenge**: Can you figure out how to get rid of the extra bits of line at the bottom? Or can you adjust the window so that the lines are only visible where you want them.