Posted by Sandra on .
1.Write 4+6+8+10 in sigma notation:
I came up with sigma in the middle
3 on top
j=0 on the bottom
2n+4 to the right of the signma sign
2. Find the 10th term of the sequence
1/5,1/20,1/80 this was a geometric sequence so I said a(subscript10) = 1/5*1/4^(101)
=1/5*(1/4)^9 = 1/5*1/2621444
= 1/1310702

PreCalcPlease check answer 
Sandra,
Should be sigma sign not signma sign

PreCalcPlease check answer 
Steve,
1. either have n=0 under the sigma, or use (2j+4) as the summand.
2. good work, but
4^9 = 262144. you have an extra 4.
1/5 * 1/262144 = 1/1310720
that dyslexia will get you every time. I noticed it right off, because no multiple of 5 ends in 2 :)
did you hear about the dyslexic devil worshiper? He sold his soul to Santa. 
PreCalcPlease check answer 
Sandra,
Thank youI see where I made the mistake
Funny!! I like that!