\mathbf r
x=x\left(u,v\right)
y=y\left(u,v\right)
z=z\left(u,v\right)
\left(x,y,z\right)

PARAMETRIZATION OF SURFACES

A function of two real variables \(z=f(x,y)\)

\(\mathbb R\) 

a unique real number \(z.\)

\((x,y)\)

\(D\)

\(f\)

assigns to each point in its domain \(D\subset \mathbb R^2\)

\(D\subset\mathbb R^2\) 

f(x,y) = x^2-y^2

Surface

Surface

f(x,y) = x^2+ y^2

Surface

f(x,y) = \sqrt{1-x^2-y^2}

Surface

f(x,y) = ???

Surface

Sphere

f(x,y) = ???

Surface

Torus

f(x,y) = ???

Surface

Helicoid

f(x,y) = ???
\left(x_1,y_1\right)
z_1=f\left(x_1,y_1\right)
z_2=f\left(x_1,y_1\right)
f(x,y) = ???
z_1 \neq z_2

It doesn't fit the definition of function!

Parametrization of surfaces

How can we defined these surfaces?

Sphere

Torus

Helicoid

Parametrization of surfaces

Parametrization of surfaces

Parametrization of surfaces

\mathbf r
x=x\left(u,v\right)
y=y\left(u,v\right)
z=z\left(u,v\right)
\left(x,y,z\right)

Parametrization of surfaces

Parametrization of surfaces

Sphere

Torus

Helicoid

x = \cos u \sin v
y = \sin u \sin v
z = \cos v
x = \cos u\left(\frac{1}{2}\cos v + 2\right)
y = \sin u \left(\frac{1}{2} \cos v + 2\right)
z = \frac{1}{2}\sin v
x = u \cos v
y = u \sin v
z = v
0\leq u\leq 2\pi
0\leq u\leq \pi
0\leq u\leq 2\pi
0\leq u\leq 2\pi
-2\leq u\leq 2
-\pi\leq u\leq \pi

GeoGebra

Math3D.org

Desmos

Patrons:

Edward Huff, Abei, pmbem, Sophia Wood, Adam Parrott, Doug Kuhlman, bleh, Miguel Díaz, Ruan Ramon, Maciej Lasota, Christopher-Alexander Hermanns, Aarón Reyes, Gabriela Sofia Marin Sánchez, Jerome Siegler, Yashar Shoraka, Jeff Butterworth, Shaun MacMillan, Scott Pedersen, Ihsan Karabulut, Elias Sanchez Angarano, Emanuel Silva

Thanks for

watching!

Thanks for

watching!

Patrons:

Edward Huff, Abei, pmbem, Sophia Wood, Adam Parrott, Doug Kuhlman, bleh, Miguel Díaz, Ruan Ramon, Maciej Lasota, Christopher-Alexander Hermanns, Aarón Reyes, Gabriela Sofia Marin Sánchez, Jerome Siegler, Yashar Shoraka, Jeff Butterworth, Shaun MacMillan, Scott Pedersen, Ihsan Karabulut, Elias Sanchez Angarano, Emanuel Silva

Parametric surfaces

By Juan Carlos Ponce Campuzano

Parametric surfaces

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