Q. What is the area of the region between the graphs of f(x)=x2−3x and g(x)=2x from x=0 to x=5 ?Choose 1 answer:(A) 6175(B) 25(C) 6325(D) 6125
Set up integral: Set up the integral to find the area between the two curves. The area A between the two curves from x=a to x=b is given by the integral of the top function minus the bottom function, from a to b. In this case, we need to determine which function is on top (greater y-value) for the interval from x=0 to x=5.
Compare functions at point: Compare the functions at a point to determine which is on top. Let's evaluate both functions at a point within the interval, say x=1. f(1)=12−3(1)=1−3=−2g(1)=2(1)=2 Since g(1) > f(1), we can assume that g(x) is the top function for the interval. However, we should verify this for the entire interval to be certain.
Verify functions for interval: Verify that g(x) is above f(x) for the entire interval from x=0 to x=5. We can do this by finding the points of intersection, if any, between f(x) and g(x) within the interval. Set f(x) equal to g(x) and solve for x: x2−3x=2xf(x)0f(x)1x=0 or x=5 The functions intersect at the endpoints of the interval, so g(x) is indeed above f(x) for the entire interval from x=0 to x=5.
Set up definite integral: Set up the definite integral to find the area.The area A is given by the integral from 0 to 5 of (g(x)−f(x))dx.A=∫05(2x−(x2−3x))dxA=∫05(−x2+5x)dx
Calculate integral: Calculate the integral.A=∫05(−x2+5x)dxTo integrate, we find the antiderivative:A = \left[\frac{\(-1\)}{\(3\)}x^\(3 + \frac{5}{2}x^2\right]_{0}^{5}
Evaluate antiderivative: Evaluate the antiderivative at the upper and lower limits of integration.A=[(−31)(5)3+(25)(5)2]−[(−31)(0)3+(25)(0)2]A=[(−31)(125)+(25)(25)]−[0+0]A=[(−3125)+(2125)]
Simplify expression: Simplify the expression to find the area.A=[(−125/3)+(125/2)]To combine the fractions, find a common denominator, which is 6:A=[(−250/6)+(375/6)]A=(125/6)
Check for errors: Check for any mathematical errors in the calculations.Re-evaluate the antiderivative and the arithmetic to ensure there are no errors.
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