$0\le y\le 2^{x}0\backslash leq\; y\backslash leq2^x$

$0\le y\le {\left(\frac{1}{2}\right)}^{x}0\backslash leq\; y\backslash leq\backslash left(\backslash frac12\backslash right)^x$

$0\le y\le 2\cdot 2^{x}0\backslash leq\; y\backslash leq2\backslash cdot2^x$ und $0\le y\le 2\cdot {\left(\frac{1}{2}\right)}^{x}0\backslash leq\; y\backslash leq2\backslash cdot\backslash left(\backslash frac12\backslash right)^x$

$2^x\le y\le 42^x\backslash leq\; y\backslash leq4$ und ${\left(\frac{1}{2}\right)}^x\le y\le 4\backslash left(\backslash frac12\backslash right)^\{x\backslash ;\}\backslash leq\; y\backslash leq4$