Question

if the first two terms of AP are -3 and +4, then find it's 12th term.​

Answer 1

Answer:

Here, a = -3 and d = 7

∴ t12 = a + 11d

∴ t12 = -3 + 77 = 74

Answer 2

Given : First two terms of an AP are -3 and 4

To Find : 12th term of the AP.

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Here

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• First term, T1 = -3
• Second term, T2 = 4

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Here, first term and second term is given. Now we'll find the Common difference of the AP.

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Common difference -

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• Second term - First term => T2 - T1 => 4 - (-3) => 7

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For finding any term of the AP, formula is given as,

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$\star \: \underline{\boxed{\sf\pink{T_{n} = a + (n - 1)d}}}$

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❍ Where, n denotes number of term , a denotes first term and d denotes common difference.

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$\sf:\implies \: T_{n} = a + (n - 1)d \\ \\ \\ \sf:\implies \: T_{12} = ( - 3) + (12 - 1)7 \\ \\ \\ \sf:\implies \: T_{12} = ( - 3) + 11 \times 7 \\ \\ \\ \sf:\implies \: T_{12} = ( - 3) + 77 \\ \\ \\ \sf:\implies \: \underline{\boxed{\mathfrak\purple{T_{12} = 74}}} \: \bigstar \\ \\ \\ \\ \sf \therefore{ \underline{Hence ,\: the \: 12th \: term \: of \: the \: AP\: is \: \bold{74}.}}$