HP 40gs hp 40gs_user's guide_English_E_HDPMSG40E07A.pdf - Page 282

hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM Press again to simplify the result to Y = 2X+5. Second method Type: (-3,-1 )-(-1,3) The answer is -(2+4i). Exercise 6 16-8 With the answer still selected, apply the ABS command by pressing . Pressing gives 2 5 , the same answer as with method 1 above. You can also determi1ne the equation of the line AB by typing: DROITE(( -1,3), (-3,-1)) Pressing then gives the result obtained before: Y = -(2X+5). In this exercise, we consider some examples of integer arithmetic. Part 1 For n, a strictly positive integer, we define: an = 4 × 10n - 1, bn = 2 × 10n - 1, cn= 2 × 10n + 1 1. Compute a1, b1, c1, a2, b2, c2, a3, b3 and c3. 2. Determine how many digits the decimal representations of an and cn can have. Show that an and cn are divisible by 3. 3. Using a list of prime numbers less than 100, show that b3 is a prime. Step-by-Step Examples