Eliminate exponential and trigonometric parameters

Find the Cartesian equation for each curve and give restrictions on $x$ where possible.

(i) $x=e^t$, $y=e^{3t}$.

(ii) $x=\ln t$, $y=\sqrt t$, for $t>0$.

(iii) $x=5+4\sec\theta$, $y=1+\tan\theta$.