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Question
The total revenue in rupees received from the sale of x units of a product is given by R(x) = 13x2 + 26x + 15. Find the marginal revenue when x = 7.
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Solution
R(x) = 13x2 + 26x + 15
Marginal revenue `= (dR)/dx = d/dx`
`(13x^2 + 26x + 15)`
= 13 × 2x + 26
= 26x + 26
∴ (MR)x=7
= 26 × 7 + 26
= 182 + 26
= 208
Marginal revenue (when x = 7) = Rs. 208
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