# Thread: [SOLVED] Equation of the tangent plane to a parametrized surface

1. ## [SOLVED] Equation of the tangent plane to a parametrized surface

I'm pretty sure I'm making a small mistake on these problems. I've done several they way I'm sure it's done, and rechecked them and they always come back as incorrect.
Here's an example problem:

$r(u,v) = (-3u, 2u^2-4v, 5v^2)$ at the point (9, 6, 45)

From this I get that:
$(u,v) = (-3,3)$
$r_u = (-3,-12,0)$
$r_v = (0, -4, 30)$

$-360x - 90y + 12z + 3240 = 0$