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Sequences and Series QUESTION

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RL989:
Hi
could I please have some help with the attached questions:

thanks!!

jamonwindeyer:

--- Quote from: RL989 on August 28, 2018, 04:49:12 pm ---Hi
could I please have some help with the attached questions:

thanks!!

--- End quote ---

Hey! So for that first one, use the sum formula and substitute into the LHS:



Try and make that look like \(T_n\), that is, like \(a+(n-1)d\). It is just grouping and cancellation ;D
Next one, take the sum of all integers from 1 to 100, and subtract the sum of all multiples of 6 from 1 to 100.



The difference of those is your answer!
Finally, if we have 49 terms that add to 233, and 50 terms that add to 249, then that 50th term must be the difference between them! So, 249-233=16! ;D
Hope this helps, let me know if you wanted me to explain anything in a little more detail :)

RL989:

--- Quote from: jamonwindeyer on August 28, 2018, 07:06:06 pm ---Hey! So for that first one, use the sum formula and substitute into the LHS:



Try and make that look like \(T_n\), that is, like \(a+(n-1)d\). It is just grouping and cancellation ;D
Next one, take the sum of all integers from 1 to 100, and subtract the sum of all multiples of 6 from 1 to 100.



The difference of those is your answer!
Finally, if we have 49 terms that add to 233, and 50 terms that add to 249, then that 50th term must be the difference between them! So, 249-233=16! ;D
Hope this helps, let me know if you wanted me to explain anything in a little more detail :)

--- End quote ---


thank you so much!!  :D

RL989:
Hi,
Could I please have some help with the following questions from the sequences and series topic.
thank you.

RuiAce:

--- Quote from: RL989 on September 03, 2018, 08:37:28 pm ---Hi,
Could I please have some help with the following questions from the sequences and series topic.
thank you.

--- End quote ---



In Q13 once again you have a geometric sequence and this time you have \(a = 25000\) and \(r = 1.05\). You are required to calculate \(T_6\) and \(S_6\).


You should be able to clean up the gaps.

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