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Question
If A = pr2 and C = 2pr, then express r in terms of A and C.
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Solution
A = pr2 ....(i) and C = 2pr ....(ii)
Divide (i) by (ii)
`"A"/"C" = "pr"^2/(2"pr")`
⇒ `"A"/"C" = "r"/(2)`
⇒ r = `(2"A")/"C"` ....(Multiplying throughout by r)
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