The equation of the plane that is tangent to the surface xyz = 8 at po...
Suppose T(x,y,z) be any point on tangent plane
is normal to surface
at point P(1,2,4). Therefore,
is perpendicular to vector
lying in the tangent plane of the given surface.
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The equation of the plane that is tangent to the surface xyz = 8 at po...
Solution:
The equation of the given surface is xyz = 8.
To find the equation of the plane that is tangent to the surface at point (1, 2, 4), we need to find the normal vector to the surface at that point and then use it to write the equation of the tangent plane.
Finding the normal vector:
Let F(x, y, z) = xyz - 8
Then, the gradient of F at point (1, 2, 4) gives the normal vector to the surface at that point.
∇F = [∂F/∂x, ∂F/∂y, ∂F/∂z]
∂F/∂x = yz, ∂F/∂y = xz, ∂F/∂z = xy
So, ∇F(1, 2, 4) = [2(4), 1(4), 1(2)] = [8, 4, 2]
Thus, the normal vector to the surface at point (1, 2, 4) is [8, 4, 2].
Writing the equation of the tangent plane:
The equation of the plane passing through point (1, 2, 4) with normal vector [8, 4, 2] is given by:
8(x-1) + 4(y-2) + 2(z-4) = 0
Simplifying:
8x - 4y - 2z = -12
Multiplying by -1/2 to get the coefficients of x, y, and z to be integers:
-4x + 2y + z = 6
Thus, the equation of the plane that is tangent to the surface xyz = 8 at point (1, 2, 4) is 4x - 2y - z = -6, which is equivalent to option (B).
The equation of the plane that is tangent to the surface xyz = 8 at po...
By placing values x≈1, y=2, z=4 we get
4+4+4= 12
12=12