Respuesta :
Letting [tex]x=t[/tex], we get [tex]y=3x^2=3t^2[/tex] and [tex]z=7x^2+y^2=7t^2+(3t^2)^2=7t^2+9t^4[/tex], so we can parameterize the intersection by
[tex]\mathbf r(t)=\langle t,3t^2,7t^2+9t^4\rangle[/tex]
where [tex]-\infty<t<\infty[/tex].
Image attached.
[tex]\mathbf r(t)=\langle t,3t^2,7t^2+9t^4\rangle[/tex]
where [tex]-\infty<t<\infty[/tex].
Image attached.

A vector function r(t) is represented as: [tex]r(t) = <x,y,z>[/tex]
The vector function r(t) that represents the intersection of the two surfaces is [tex]r(t) = <t,3t^,7t^2 + 9t^4>[/tex]
Given
[tex]z = 7x^2+ y^2[/tex]
[tex]y = 3x^2[/tex]
Let
[tex]x = t[/tex]
Substitute [tex]x = t[/tex] in [tex]y = 3x^2[/tex] and [tex]z = 7x^2+ y^2[/tex]
[tex]y = 3t^2[/tex]
[tex]z = 7t^2 + y^2[/tex]
Substitute [tex]y = 3t^2[/tex] in [tex]z = 7t^2 + y^2[/tex]
[tex]z = 7t^2 +(3t^2)^2[/tex]
[tex]z = 7t^2 +9t^4[/tex]
Recall that:
[tex]r(t) = <x,y,z>[/tex]
Substitute the values of x, y and z.
[tex]r(t) = <t,3t^,7t^2 + 9t^4>[/tex]
Hence, the vector function r(t) is:
[tex]r(t) = <t,3t^,7t^2 + 9t^4>[/tex]
Read more about vector functions at:
https://brainly.com/question/4515610