(Solved):   1. Given \( z=\left(x^{2}+4 y^{2}\right)^{1 / 2} \), find the equation of the tangent plan ...

 

1. Given \( z=\left(x^{2}+4 y^{2}\right)^{1 / 2} \), find the equation of the tangent plane at \( (0,1,2) \). 2. Given \( f(x, y)=3 x^{2} y^{3} \) with \( x=2-3 \ln (t), y=w s^{2} \) and that \( s=w^{*} \cos (v), t=v^{2} u \). Draw the variable tree. Find \( f_{v} \) and \( f_{w} \) -