HP Forum Archive 17

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Summation on HP48G? Message #1 Posted by Ren on 24 Oct 2007, 3:03 p.m. Hello, In my Software Testing class, the text said that a graph with 5 possible paths and up to 18 iterations(loop) could equal 4.77 Trillion test cases. Our assignment was to figure out how the author arrived at that figure. Well, I didn't get it figured out before the deadline... but a couple of classmates said it was a Summation problem. 18 on top of the Sigma, 5^i right of the Sigma and i = 1 on the bottom of the Sigma. My HP48G has a Sigma (Green shift TAN) but I haven't figured out how to use it. Could someone show me how? Sincerely, the Klutzy Math Groupie, Ren dona nobis pacem

Re: Summation on HP48G? Message #2 Posted by Alex L on 24 Oct 2007, 3:26 p.m., in response to message #1 by Ren Here are the keystrokes to accomplish this with the equation editor, so it looks just like you'd see in the textbook: EQUATION (Left-shift ENTER) SIGMA (Right-shift TAN) I=1 -> (right arrow) 18 -> 5 y^x I ENTER That puts the sum on the stack as an algebraic object, which also shows you how to type it in directly without the equation editor. To then get the sum, use EVAL.

Thanks! WAS: Re: Summation on HP48G? Message #3 Posted by Ren on 24 Oct 2007, 4:00 p.m., in response to message #2 by Alex L Yippee! I was paging through the HP48 pdf and when I saw the references to Equation writer, something in my head said, "it's gotta be easier than that, it's right there on the keyboard". Thanks again! Ren dona nobis pacem

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