Jawapan

2016-06-11T04:04:42+08:00
A)r= \frac{0.09}{-0.03} =  \frac{-0.03}{0.01}  = -3
  Tn=a r^{n-1}
  65.61=0.01 (-3)^{n-1}
   3^{8} =  (-3)^{n-1}
8=n-1
n=9 
T8=-21.87

b) r= \frac{-1}{9} bahagi \frac{1}{3} =  \frac{1}{27} bahagi \frac{-1}{9} =  \frac{-1}{3}  
   \frac{-1}{59049} =  \frac{1}{3}   r^{n-1}
  \frac{1}{3} ^{10} =     \frac{1}{3} ^{n-1} 

10=n-1
n=11 \frac{-1}{6561}