Hi there!
1. To estimate f(1) we have to find the outcome (y-value) after the input of x = 1. Following the graph shows that x = 1 is put in, the value of y = 2. So f (1) = 2.
2. To find x such that f (x) = 0 we have to find a value of x where the y-value of the function equals zero. This point is also known as the x-intercept. Following the graph, we can see that the input of x = 2 gives y = 0. Therefore f (x) = 0 gives x = 2.