Answer:The answer is f(-4) = -4 ,f(-3.1) = -3.1 , f(1.2) = 1.2 , f(2.8) = 2.8Step-by-step explanation: We have to find out f(-4) , f(-3.1) , f(1.2) , f(2.8) For the condition f(x) = x This means that whatever we give input to the function the value to the function is equal to the value input this means that f (input) = output Here output = input f ( input ) = input ∵ f(-4) = -4 f(-3.1) = -3.1 f(1.2) = 1.2 f(2.8) = 2.8