- (a) Sketch the graph of \(y = 7 ^ { x } , x \in \mathbb { R }\), showing the coordinates of any points at which the graph crosses the axes.
(b) Solve the equation
$$7 ^ { 2 x } - 4 \left( 7 ^ { x } \right) + 3 = 0$$
giving your answers to 2 decimal places where appropriate.