Find parametric equations for the line tangent to the curve of intersection of the surfaces at the given point surfaces:

x^2 + y^2 = 4, y=1

Point: (1/2, 1, 1/2)

Respuesta :

Answer:

The  parametric equation is  

   [tex]x =  \frac{1}{2}[/tex]

   [tex]y  =  1[/tex]

  [tex]z =  \frac{1}{2}  +  t[/tex]

Step-by-step explanation:

From the  question we are told that

   The  equation given are  

               [tex]x^2 + y^2 = 4[/tex]

           and  y =  1  

Thus

  Let  

     [tex]f(x,y,z) = x^2 + y^2 -4 = 0[/tex]

  And  [tex]g(x,y,z ) = y- 1[/tex]

Now  we will differentiate f(x, y , z ) and  g(x,y,z) to obtain value  of f(x,y,z )  and    g(x,y,z) where the line passed through

 So

     [tex]\Delta f(x,y,z) = 2x + 2y + 0z[/tex]

At  Point: (1/2, 1, 1/2)

    [tex]\Delta f(1/2,1 ,1/2) = 2 (1/2) + 2(1) + 0(1/2)[/tex]

    [tex]\Delta f(1/2,1 ,1/2) = 1 + 2 + 0[/tex]

converting to coordinate form

   [tex]\Delta f(1/2,1 ,1/2) = <1 \ , 2 \ ,0>[/tex]

And

    [tex]\Delta g(x,y,z) = 0x + 1 + 0z[/tex]

At  Point: (1/2, 1, 1/2)

    [tex]\Delta g(1/2,1 ,1/2) = 0 (1/2) + 1 + 0(1/2)[/tex]

converting to coordinate form

   [tex]\Delta g(1/2,1 ,1/2) \ = \ <0 \ , 1 \ , 0 >[/tex]

At point of intersection we have that

    [tex]G  =  \Delta  f  \  X  \  \Delta g  = | det  \left[\begin{array}{ccc}i&j&k\\1&2&0\\0&1&0\end{array}\right] |[/tex]

=> [tex]G  = i((2 *  0 ) - (0 *  1))-  j  ((1 *  0 ) - (0*0)) +  k((1 * 1 ) - (2 *  0))[/tex]

=>  [tex]G   = 0i - j (0) +  k[/tex]

Thus the parametric equation is  

      [tex]x =  \frac{1}{ 2} -  0 t[/tex]

=>    [tex]x =  \frac{1}{2}[/tex]

 [tex]y =  1 -  0(t)[/tex]

=>    [tex]y  =  1[/tex]

and  

     [tex]z =  \frac{1}{2}  +  t[/tex]

   

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