Page 231 - aljaber
P. 231
@ @¶ìÿa@óÝy‹¾a@ u@ @RQX
n 1400
.an > 1400
.a17 = 1536 a16 = 768 2 a15 = 768
a17
.
.
.162 −6 ()
.
( ) a2 = a1r = −6
( ) a5 = a1r 4 = 162
() ()
a1r 4 = 162 r = −3 a1 = 2
a1r −6
()
r 3 = −27 .9
r = 3 −27
r = −3
.an = 2 × (−3)n−1
20 2
.
