Suppose that (x1,y1) and (x2,y2) are points on the unit circle, and that, viewing the points as rays through the origin, the angle between them is t. Show that cos(t)=x1*x2+y1*y2.
Repeat the argument used in class on the sum 1+16+3^4+4^4+....+n^4 to find the formula for 1+8+3^3+... +n^3. (This is essentiallly problem 30)
Section 4.1: 10, 12, 18, 22, 27, 28, 42, 55, 61