10 The equation of a curve is \(y = \sqrt { } ( 5 x + 4 )\).
- Calculate the gradient of the curve at the point where \(x = 1\).
- A point with coordinates \(( x , y )\) moves along the curve in such a way that the rate of increase of \(x\) has the constant value 0.03 units per second. Find the rate of increase of \(y\) at the instant when \(x = 1\).
- Find the area enclosed by the curve, the \(x\)-axis, the \(y\)-axis and the line \(x = 1\).