Ok, last one for tonight, i can't believe i am stuck on this one:

Find the maximum height above the https://webwork.math.lsu.edu/webwork...4304f3b401.png-plane of a point on

https://webwork.math.lsu.edu/webwork...6513544531.png

So i get the answer to be and the point to be but this answer is wrong, i know it is .something that is simple that i cannot figure out. (Headbang)

Thanks for your time!! (Bow)