# Math Help - How to do this question?

1. ## How to do this question?

Find equations of
1. the tangent plane and,
2. the normal line to the surface represented by the equation:
$yz = ln(x+z)$
at the point (0,0,1).

Thanks

2. Originally Posted by zen-x
Find equations of
1. the tangent plane and,
2. the normal line to the surface represented by the equation: $yz = ln(x+z)$ at the point (0,0,1).
If $F = yz - \ln \left( {x + z} \right)$ then the vector you need is $\nabla F\left( {0,0,1} \right)$.