Step 1: Definition of direction cosines.
The direction cosines of the coordinate axes \( x \), \( y \), and \( z \) are the cosines of the angles that the respective axes make with the coordinate axes. The direction cosines of the \( x \)-axis, \( y \)-axis, and \( z \)-axis are:
\[
\cos \alpha = 1, \cos \beta = 0, \cos \gamma = 0.
\]
Step 2: Conclusion.
Thus, the direction cosines of the \( x \), \( y \), and \( z \)-axes are 1, 0, and 0 respectively.
If \( y = \sqrt{e^x} \), \( x > 0 \), then \( \frac{dy}{dx} = \underline{\hspace{2cm}} \)