Question

(Score for Question 3:

Answer 1

Answer:

It's a rotation of 90 degrees - doesn't matter which way - around the intersection of the two lines

Step-by-step explanation:

Claim: it's a 90 degree rotation around the intersection of f and g.

It's easy to spot the two lines  are perpendicular. Let's assume the rotation doesn't happen at the point of intersection $x_0$, but slightly to the side, around let's say, $x_0+\epsilon$; the new line will coincide with $g(x)$ if and only if $\epsilon = 0$, ie only the rotation happens around the intersection.