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Use the information given to identify the a_9 term of the geometric sequence: a_4=1/2, r=1/2

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a given term in a PG =a₁rⁿ⁻¹

Let' calculate the 1st term a₁, knowing a term & the common factor/ratio

a₄ = 1/2 so 1/2 = a₁(1/2)³

1/2 = a₁/8 and a₁ = 4

Now calculate a₉ =a₁.r⁸

a₉ = 4.(1/2)⁸ and a₉ = 1/64


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