Find the tangent planes to $f(x,y) = 2+x^2 + y^2$ that contain the $x$ axis
136168
Tangent planes to $2+x^2+y^2$ and that contains the $x$ axis
60202
Find a plane that passes through a point and is perpendicular to 2 planes
27809
Find the function equation $f(x+f(y)+yf(x))=y+f(x)+xf(y)$
9293
Having a plane equation equaled to zero for calculating its angle with another plane
128721
Finding the equation of an ellipse tangent to two lines
7158
Using implicit differentiation to find a line that is tangent to a curve at a point
61641
Equations of lines tangent to an ellipse
88184
Finding the value of $k$ for parallel/orthogonal planes
122329
Determine all functions $f(x)$ such that $f(f(x+y))=f(x)+f(y)$
105280
How to find the equation of a parabola given the tangent equations to two points?
70991
Find the equation of the plane knowing that it passes through 3 points
61307
Consider the surface $S$ in $\mathbb{R}^ 3$ given by the graph of $f(x, y) = xy^2 − 2y^2 + e^x $.
19474
Find all solutions to the functional equation $f(x) +f(x+y)=y+2 $
105506
Finding the Total Curvature of Plane Curves
115737
Tangent and Normal lines that pass through the origin
93436
What is the gradient of $f(x, y, z) = \sqrt{x^2+y^2+z^2}$?
103251
Solution(s) to $f(x + y) = f(x) + f(y)$ (and miscellaneous questions...)