PATTERNS, FUR1 2010 VCAA 4 MC The first four terms of a geometric sequence are `4, – 8, 16, – 32` The sum of the first ten terms of this sequence is A. `–2048` B. `–1364` C. `684` D. `1367` E. `4096` Show Answers Only `B` Show Worked Solution `4, –8, 16, –32)`♦ Mean mark 41%. `text(GP where)\ \ \ a` `= 4` `r` `=t_(2)/t_(1)= (–8)/4=–2` `S_n` `=(a(r^n – 1))/(r – 1)` `:.S_10` `=[4[(–2)^10 – 1]]/(–2 – 1)` `= –1364` `=> B`