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Question
Find the third proportional to a2 – b2 and a + b.
Solution
Let the third proportional to a2 – b2 and a + b be n.
`=>` a2 – b2, a + b and n are in continued proportion.
`=>` a2 – b2 : a + b = a + b : n
`=> n = (a + b)^2/(a^2 - b^2)`
= `(a + b)^2/((a + b)(a - b))`
= `(a + b)/(a - b)`
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