a)Find the equation of the tangent plane to the graph z = x(adsbygoogle = window.adsbygoogle || []).push({}); ^{2}+ 4y^{2}at the point (a, b, a^{2}+ 4b^{2})

b) For what values of a and b is the tangent plane perpendicular to the vector (3, -4, 2)?

I figured you have to use the tangent plane equation z - z_{o}= z_{x}(a,b)(x-a) + z_{y}(a,b)(y-b). This gave me the equation

Z = 2ax + 8by - a^{2}- 4b^{2}

Forb, I think the dot product could be used if I set it to zero. But how would I go about solving for a and b? I think I may just be getting tired and a bit sloppy, because I know this is already stuff I have gone over, the only new thing is solving for a and b.

Any direction on this would be great, I'm just having trouble visualizing this problem.

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# Homework Help: Planes perpendicular to vectors

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