c2 geometric series

Hi room,
I have a problem with this question.

I have looked at the solutions but the answer on my calculator is different to the one shown in the solution

Attachment not found

I dont understand why the solution given in the solution bank is not negative

S(14) is smaller than the sum to infinity

Thank you for the help

Original post by bigmansouf

Hi room,
I have a problem with this question.

I have looked at the solutions but the answer on my calculator is different to the one shown in the solution

Attachment not found

I dont understand why the solution given in the solution bank is not negative

S(14) is smaller than the sum to infinity

Thank you for the help

Obviously a typing error in the book solution

Reply 2

thenextchemist

Solution bank is rarely wrong, so I suggest you follow that throughout your studies of C2

Posted from TSR Mobile

Reply 3

mik1a

A difference can't be negative. What's the difference between 5 and 8? 3. What's the difference between 8 and 5? 3. Think of "difference" as a quantity with magnitude but no sign. Or just translate it as "positive difference" in your head.

You are also allowed to round the number. Since they gave you a rounded number in the question ("5.12") which has three significant figures, you should aim to follow that convention and round to 8.95x10^-4.