Find a vector function that represents the curve of the intersection of the two surfaces. The cylinder x2 + y2 = 4 and the surface z = xy.
Solution:
Given, the equation of the cylinder is x2 + y2 = 4
Given, the equation of the surface is z = xy
We have to find the vector function that represents the curve of the intersection of the two surfaces.
A vector function is represented as
r(t) = xti +ytj + ztk --- (1)
The equation of cylinder can be written as x2 + y2 = (2)2 × 1
From trigonometric identity,
cos2t + sin2t = 1
Substituting the trigonometric identity,
x2 + y2 = (2)2[cos2t + sin2t]
x2 + y2 = 22 cos2t + 22 sin2t
x2 + y2 = [2 cost]2 + [2 sint]2
By comparison,
xv = [2 cost]2
x = 2 cost
y2 = [2 sint]2
y = 2 sint
Also, z = xy
z = (2 cost)(2 sint)
z = 4 cost sint
Substituting the values of x, y and z in (1),
r(t) = (2 cost)i + (2 sint)j + (4 cost sint)i
Therefore, the vector function that represents the intersection of the two surfaces is
r(t) = (2 cost)i + (2 sint)j + (4 cost sint)i.
Find a vector function that represents the curve of the intersection of the two surfaces. The cylinder x2 + y2 = 4 and the surface z = xy.
Summary:
A vector function that represents the curve of intersection of the two surfaces. The cylinder x2 + y2 = 4 and the surface z = xy is r(t) = (2 cost)i + (2 sint)j + (4 cost sint)i.
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