This week, we continued the chapter, Functions. And we go in deeper for this chapter, to calculate functions, as we have known that the x is the input and the y is the output. When we see a question like f(x)=2x+3. The f refers to the name of the function. the (x) is the input x the output y is 2x+3. Usually, x will be given as a number in order to calculate y . for example f(5)=2x+3. in this case, it means x=5 then, we have the sub the number 5  into 2(5)+3. then we can get the output. But in other cases, we will be given a graph to find out.

y.