write the parametric representation of
$\large \rm z=4x^2+y^2$

Question

write the parametric representation of
$\large \rm z=4x^2+y^2$

anonymous · Answer

is it
z=4t
x=2sin t
y=4cos t 
?

tkhunny · Answer

Well, let's see...  Take t = 0

z=4t = 4(0) = 0
x=2sin t = 2(0) = 0
y=4cos t  = 4(1) = 4

0 = 4(0^2) + 4^2 = 0+16 = 16 <== Well, THAT doesn't seem right!

anonymous · Answer

oh God :(
so whats the right presentation ?

anonymous · Answer

@rational

rational · Answer

x = 1/2cost
y = sint

wont this work ?

anonymous · Answer

and z= ?

rational · Answer

x=2sin t
y=4cos t 

also is fine right ? im not sure what you are parameterizing it for...

z = 1 i guess

anonymous · Answer

ermm |dw:1400090475531:dw|

rational · Answer

since its a surface we need two variables may be... idk im at temporary memory loss :s

rational · Answer

Alright, it looks bit complicated http://tutorial.math.lamar.edu/Classes/CalcIII/ParametricSurfaces.aspx

anonymous · Answer

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