I am not getting the 10th first term and last term | Mathematics | Page 1

haughty fractal Apr 21, 2025, 4:06 PM

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rancid tartanBOT Apr 21, 2025, 4:06 PM

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haughty fractal Apr 21, 2025, 4:10 PM

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@pure wing

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Can u help me in this

unique matrixBOT Apr 21, 2025, 4:20 PM

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haughty fractal Apr 21, 2025, 4:23 PM

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Ye

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That's the part I am messing

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Ye

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Ye

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No

gray lynx Apr 21, 2025, 4:25 PM

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haughty fractal Apr 21, 2025, 4:26 PM

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Yoo

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How

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We have to find it

gray lynx Apr 21, 2025, 4:27 PM

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first term in each row forms a quadratic sequence

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i just solved for that

haughty fractal Apr 21, 2025, 4:28 PM

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K

gray lynx Apr 21, 2025, 4:28 PM

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where is this question from

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pretty nice tbf

haughty fractal Apr 21, 2025, 4:28 PM

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How did u find un

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Sam where u from

gray lynx Apr 21, 2025, 4:28 PM

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haughty fractal How did u find un

that’s just the arithmetic sequence formular

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nth term

haughty fractal Apr 21, 2025, 4:29 PM

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Or

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Why

gray lynx Apr 21, 2025, 4:29 PM

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u don’t rlly need to work it out u can kinda see it from the sequence

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2,5,… follows 3n-1

haughty fractal Apr 21, 2025, 4:29 PM

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The question is from jee mains 2024 pyq

gleaming ore Apr 21, 2025, 4:30 PM

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haughty fractal

try to understand the pattern
and do it manually

gray lynx Apr 21, 2025, 4:30 PM

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haughty fractal Sam where u from

uk

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then Rn is just the first term of each row

haughty fractal Apr 21, 2025, 4:30 PM

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rn_image_picker_lib_temp_68070f60-b028-43ec-b628-368939713fc8.jpg

gray lynx Apr 21, 2025, 4:30 PM

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it follows a quadratic sequence

gray lynx Apr 21, 2025, 4:30 PM

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haughty fractal

is this Rn

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i can show u how to find it

haughty fractal Apr 21, 2025, 4:31 PM

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What is meant by r

gray lynx Apr 21, 2025, 4:31 PM

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doesn’t mean anything

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just a name for the first term of each row

haughty fractal Apr 21, 2025, 4:31 PM

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Lol

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I wrote tn in formula

gray lynx Apr 21, 2025, 4:31 PM

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do u know how to find Tn then

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i can show u

haughty fractal Apr 21, 2025, 4:32 PM

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Ok now what to subtitute in formula

gray lynx Apr 21, 2025, 4:32 PM

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yes like this

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do u know matrices or nah

gleaming ore Apr 21, 2025, 4:32 PM

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haughty fractal

dude analyse the pattern
and try to do it manually

gray lynx Apr 21, 2025, 4:32 PM

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i can do without them

gray lynx Apr 21, 2025, 4:33 PM

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gleaming ore dude analyse the pattern and try to do it manually

yeah but learning to do it like this works much better for harder questions

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ie sum of the Nth row

haughty fractal Apr 21, 2025, 4:33 PM

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gleaming ore dude analyse the pattern and try to do it manually

That's the part where I am messing up on analysing

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I understand the question

gray lynx Apr 21, 2025, 4:34 PM

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look at the pattern for the first number in each row

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then find the number on the 10th row

haughty fractal Apr 21, 2025, 4:34 PM

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Oh I understand

gray lynx Apr 21, 2025, 4:34 PM

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set 3n-1=to that number

haughty fractal Apr 21, 2025, 4:35 PM

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How did u get 3n_1

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3n-1

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Oh

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I see

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An=a+(n-1)d

gray lynx Apr 21, 2025, 4:37 PM

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yes

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u don’t rlly need to use that formula tho

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it’s quicker to just do (d)n + (a-d)

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so whatever the difference is that’s the coefficient of n

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then just do the first term minus the difference

haughty fractal Apr 21, 2025, 4:41 PM

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So I got tn

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I mean t10th 137

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The I get last term

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Yoo I got it

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Thanks

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@gray lynx

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.solved

rancid tartanBOT Apr 21, 2025, 4:45 PM

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Solved

Post marked as solved by @haughty fractal.

Use .unsolved if this was a mistake.

gleaming ore Apr 21, 2025, 4:48 PM

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haughty fractal So I got tn

Ans: 1520 right

haughty fractal Apr 21, 2025, 4:49 PM

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I got 1505

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Get first term and last term

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By using quadratic formula

gleaming ore Apr 21, 2025, 4:50 PM

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last term is 167

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??

gleaming ore Apr 21, 2025, 4:52 PM

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haughty fractal By using quadratic formula

seriously , why quadratic formula

haughty fractal Apr 21, 2025, 4:52 PM

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Tn=ar^2+br+c

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Tn is no.of term and r is no.of row

gleaming ore Apr 21, 2025, 4:54 PM

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haughty fractal Tn=ar^2+br+c

Well i approached it differently
what is last term you got
56th

haughty fractal Apr 21, 2025, 4:54 PM

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164

gleaming ore Apr 21, 2025, 4:54 PM

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it is 167

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nah my bad
you are right

gleaming ore Apr 21, 2025, 5:03 PM

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haughty fractal 164

yeah fine dude

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au revoir.

haughty fractal Apr 21, 2025, 5:03 PM

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What

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Get first and last term with that formula then sum of the term done

gleaming ore Apr 21, 2025, 5:05 PM

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yeah i got it ,

#I am not getting the 10th first term and last term