1. If the point $(x, y)$ on the plane moves along the line $x+2 y=3$, then the minimum value of $2^{x}+4^{y}$ is
1. $4 \sqrt{2} .2^{x}+4^{y}=2^{x}+2^{2 y} \geqslant 2 \sqrt{2^{x} \cdot 2^{2 y}}=2 \sqrt{2^{x+2 y}}=4 \sqrt{2}$.