Show that

where T_k is the kth triangular number. (See Question 4 in Exercises 7.2.3.)

Data from Question 4 in Exercises 7.2.3.

Triangular numbers (T_n) are defined by the number of dots that occur when arranged in equilateral triangles, as shown in Figure 7.5. Show that T_n = 1/2n(n + 1) for every positive integer n.

Transcribed Image Text:

71 k=1 -|B Tk T-1+ T T