1. They ask you to find the minimum of the function f(x) = x +in the interval I = [1/2, 3]. Take the derivative, equate it to zero and find the root: f'(x) = 1 - ; f'(x) = 0 is the equation 1 - = 0; as an equation, it is equivalent to = 1, which has only one root x= 1 in the given interval. ANSWER. x = 1. To better illustrate the situation for you, I placed the plot below: Plot y = x + .