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Find an equation in cylindrical coordinates for the surface represented by the rectangular equation z = x² + y² - 6.

User Pangu
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Final answer:

The equation z = x² + y² - 6 in cylindrical coordinates is z = r² - 6 by substituting x with r*cos(θ) and y with r*sin(θ) into the original equation.

Step-by-step explanation:

Converting Rectangular to Cylindrical Coordinates

To find the equation of the surface z = x² + y² - 6 in cylindrical coordinates, we recall that cylindrical coordinates are related to rectangular coordinates by the relationships: x = r cos(θ), y = r sin(θ), and z = z. Here, r is the radial distance from the origin, θ is the azimuth angle, and z represents the same vertical placement as in rectangular coordinates.

Plugging the expressions for x and y in terms of r and θ into the given equation:

Replace x with r cos(θ) and y with r sin(θ).

Thus, we get z = (r cos(θ))² + (r sin(θ))² - 6.

Simplify the expression knowing that cos(θ)² + sin(θ)² = 1, which gives us z = r² - 6.

The cylindrical equation for the surface represented by the given rectangular equation z = x² + y² - 6 is z = r² - 6.

User Reallyinsane
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