\[\boxed{\mathbf{70.}}\]
\[\textbf{а)}\ x = 2y\]
\[y = \frac{x}{2} - прямая.\]
\[\textbf{б)}\ x = y^{2}\]
\[y = \sqrt{x} - положительная\]
\[\ ветвь\ параболы.\]
\[\textbf{в)}\ x = 2^{y}\]
\[y = \log_{2}x\]
\[\textbf{г)}\ x = \frac{1^{y}}{2}\]
\[y = \log_{\frac{1}{2}}x\]
\[\textbf{д)}\ x = \sin y\]
\[x = \sin\left( - \frac{\pi}{2} \right) = - \sin\left( \frac{\pi}{2} \right) = - 1;\]
\[x = \sin\left( \frac{\pi}{2} \right) = 1.\]
\[\textbf{е)}\ x = \sqrt{1 - y^{2}}\ \]
\[x^{2} = 1 - y^{2}\]
\[x^{2} + y^{2} = 1;\ \ \ x \geq 0.\]