TITLEFUNCTIONSOVERVIEWA focal concept of extreme importance in modernmathematics is the idea of functions. Functions, which dealwith corresponding relationship between the elements of twosets, are useful concepts throughout the mathematicscurriculum. In numbers and number sense, functions appear infundamental operations on numbers; in algebra, functionstakes the form of relationship between variables thatrepresent numberCONTENTSTANDARDSThe learner demonstrate understanding of key concepts offunction.PERFORMANCESTANDARDSThe learner is able to accurately construct mathematicalmodels to represent real-life situations using functionsOBJECTIVESAt the end of the lesson, students should be able to performaddition,subtractions,multiplication,division,andcomposition on functions.REFERENCE(2016). In F. B. ORINES,NEXT CENTURY MATHEMATICS(GENERAL MATHEMATICS).QUEZON CITY: PHOENIXPUBLISHING HOUSE.PURPLRMATH.(n.d.).Retrievedfrompurplemath.com/modules/invrsfen.htmDISCUSSION OF THE TOPICOPERATIONS ON FUNCTIONSSum and Difference of FunctionsIf f and g are functions with domains Dfand Dg, respectively, their sum isthe function defined as(f+g) (x)=f(x)+g(x)And their difference is the function defined as(f−g) (x)=f(x)−g(x).Example 1: Letf(x)=x+3andg(x)=x−6.Find:a. (f + g) (x)b. (f – g) (x)
Solution:a. (f + g) (x) = f(x) + g (x)Define.= (x+ 3) + (x – 6)Substitute.= x + 3 + x – 6Remove Parentheses.= (x + x) + (3 – 6)Combine like terms.= 2x – 3b. (f - g) (x) = f(x) - g (x)Define.