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Find the area of the region enclosed between the curves \(f(x) = -x^{2} + 4x + 3\) and \(g(x)\) \(=…

The area is \(\frac{49}{12}\). Here \(f(x) - g(x)\) \(= x^{3} - 8x^{2} + 14x - 2\), which is positive on [1, 2] (it equals 5 at x = 1 and 2 at x = 2, with no root in…

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Find the area of the region enclosed between the curves f(x)=−x2+4x+3f(x) = -x^{2} + 4x + 3 and g(x)g(x) =−x3+7x2−10x+5= -x^{3} + 7x^{2} - 10x + 5 over 1≤x≤21 \le x \le 2.

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The area is 4912\frac{49}{12}. Here f(x)−g(x)f(x) - g(x) =x3−8x2+14x−2= x^{3} - 8x^{2} + 14x - 2, which is positive on [1, 2] (it equals 5 at x = 1 and 2 at x = 2, with no root in between). Area =∫12(x3−8x2+14x−2) dx= \int_{1}^{2} (x^{3} - 8x^{2} + 14x - 2)\,dx =[x44−8x33+7x2−2x]12= \left[\frac{x^{4}}{4} - \frac{8x^{3}}{3} + 7x^{2} - 2x\right]_{1}^{2} =203−3112= \frac{20}{3} - \frac{31}{12} =4912= \frac{49}{12}. The other values come from slips in integrating or in subtracting the two curves.

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