• Oct 19th 2009, 12:11 PM
allhalf425
I have a big exam coming up in a few days, and there were a few problems on the study guide I couldn't get. I was hoping you guys might be able to help me out!

The first question I couldn't get goes as follows:

Find an equation of the plane tangent to the surface
3(x^2) - 4(y^2) + 6z = 26
at the point (-2, 1, 3)

Any help on this problem would be GREATLY appreciated! And please don't just give me the answer, it would be much more beneficial if you actually described what was happening. Thank you!
• Oct 19th 2009, 12:16 PM
Jameson
Quote:

Originally Posted by allhalf425
Any help on any of these problems would be GREATLY appreciated! And please don't just give me the answer, it would be much more beneficial if you actually described what was happening. Thank you!

Hi allhalf425,

Welcome to MHF.

The part of your post I quoted is a great attitude and what we do here. We aren't here to do your homework but to help you understand.

As a rule though, we like one question per thread. Six questions is just too many so please pick the one you want help with the most and show what you have attempted, if anything. Then you can make another thread for the next question, and so on.

Glad to have you and hope you stick around,
Jameson
• Oct 19th 2009, 12:45 PM
allhalf425
Fair enough! I'll edit the original post.
• Oct 20th 2009, 01:57 PM
kodos
To find the tangent plane to a surface in a given point you only need to apply a formula, but you should know where it comes from. If you're not familiar with the formula maybe you should read the topic in your textbook. Also notice you cannot apply it directly without a previous step.

$
fx(x_0,y_0)(x-x_0)+fy(x_0,y_0)(y-y_0)=z-z_0
$