## Calculus 8th Edition

$\frac{5}{2\sqrt {14}}$
Distance formula between two parallel planes is given as: $D=\frac{|ax+by+cz+d|}{\sqrt {a^2+b^2+c^2}}$ $D=\frac{|0+0+2 \times 4-3|}{\sqrt {4^2+6^2+2^2}}=\frac{5}{\sqrt {56}}$ $=\frac{5\sqrt {14}}{28}$ $=\frac{5}{2\sqrt {14}}$