Q. Use the midpoint rule to estimate- the value of ∬(x2−y2)dA where R={(x,y)∣−4≤x≤2,0≤y≤2} using three rectangles of equal area
Determine dimensions and subintervals: Determine the dimensions and subintervals for the rectangles.Since the region R is defined by −4≤x≤2 and 0≤y≤2, the width in x-direction is 6 and the height in y-direction is 2. Dividing the x-interval into three equal parts gives each rectangle a width of 2 (6/3).
Calculate x-coordinates for midpoints: Calculate the x-coordinates for the midpoints of each rectangle. The midpoints in the x-direction for the rectangles are at x=−3, −1, and 1. These are calculated by taking the middle of each interval: [−4,−2], [−2,0], and [0,2].
Calculate y-coordinate for midpoint: Calculate the y-coordinate for the midpoint of the rectangles.Since the y-interval is from 0 to 2, the midpoint in y-direction is y=1.
Evaluate function at midpoints: Evaluate the function at each midpoint.Using the function f(x,y)=x2−y2, calculate:For (−3,1): f(−3,1)=(−3)2−12=9−1=8For (−1,1): f(−1,1)=(−1)2−12=1−1=0For (1,1): f(1,1)=12−12=1−1=0
Apply midpoint rule: Apply the midpoint rule to estimate the integral.The area of each rectangle is 4 (2 in x-direction times 2 in y-direction). The integral estimate is:∬(x2−y2)dA≈(8+0+0)×4=8×4=32
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