Q. Find the volume of the given solid.bounded by the planes z=x,y=x,x+y=9 and z=0□
Sketch Region and Bounds: Sketch the region and identify the bounds.The solid is bounded by the planes z=x, y=x, x+y=9, and z=0. The intersection of the planes y=x and x+y=9 is a line in the xy-plane, which we can find by solving the system of equations.y=xx+y=9Substitute y=x into the second equation:y=x0y=x1y=x2y=x3So, the line of intersection is at the point y=x4 in the xy-plane.
Set Up Double Integral: Set up the double integral for the volume.The volume V of the solid can be found by integrating over the region in the xy-plane. The bounds for y are from y=x to y=9−x, and the bounds for x are from x=0 to x=29.V=∫∫(z)dydx, where z ranges from xy0 to x.
Compute Double Integral: Compute the double integral.V=∫x=0x=29(∫y=xy=9−x(x)dy)dxFirst, integrate with respect to y:V=∫x=0x=29(x∗(9−x)−x∗x)dxV=∫x=0x=29(9x−x2−x2)dxV=∫x=0x=29(9x−2x2)dx
Continue Integration: Continue the integration with respect to x. V=[(29)x2−(32)x3] from x=0 to x=29 Now, plug in the upper and lower bounds of x: V=(29)(29)2−(32)(29)3−((29)02−(32)03) V=(29)(481)−(32)(8729) V=(8729)−(32)(8729) V=(8729)×(1−32) V=(8729)×(31) V=[(29)x2−(32)x3]0 V=[(29)x2−(32)x3]1
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