Consider a spherical surface S given as: x2 + y2 + z2 – 9 = 0. A unit normal vector on the surface at a point P(1, 2, 2) is
1
\( \frac{{\hat 2i + 4\hat j + 4\hat k}}{{3}}\)
2
2î + 2ĵ + 2k̂
3
\(\frac{{\hat i + 2\hat j + 2\hat k}}{{3}}\)
4
î + ĵ + k̂