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For the given geometric sequence tₙ, find r if s₂=10 and s₄=50.

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Final answer:

To find the common ratio (r) in a geometric sequence, we can use the formula for the nth term of a geometric sequence. The common ratio can be found by taking the square root of the ratio of two terms in the sequence. In this case, the common ratio is ±√5.

Step-by-step explanation:

To find the common ratio (r) in a geometric sequence, we can use the formula for the nth term of a geometric sequence, which is given by:

tₙ = t₁ * r^(n-1)

From the given information, we have s₂ = 10 and s₄ = 50. Let's substitute these values into the formula:

s₂ = t₁ * r^(2-1) = t₁ * r

s₄ = t₁ * r^(4-1) = t₁ * r^3

Since we have two equations involving t₁ and r, we can solve for r by taking the ratio of the two equations:

s₄/s₂ = (t₁ * r^3) / (t₁ * r) = r^2

Substituting the given values, we get:

50/10 = r^2

Simplifying the equation, we have:

r^2 = 5

Taking the square root of both sides of the equation, we find that:

r = ±√5

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