ci When x9, y= 0. ii As the values of x increase, the corresponding values of y decrease. ii The vertical line x-7 intersects this graph once. Varation from 37'C) 45 35 8642 di The line y= 0 cuts the graph of this 32 24 25 function twice. I There are two values of x for which 2 i y=2. 1.5 il As the values of x increase, so do the corresponding values of y. ei The line y 0.5 intersects the graph 0.5 of this function twice. 02 04 0.6 O8 1 12 14 16 18 2 I The line y= 1.5 intersects the graph of this function twice. i The value x= 2 has no image. 6 Find the domain of cach of these functions if it is known that the range is (-3, -2, -1, 0, 1, 2). Times in hours since application started to work a State whether or not the relation represented in the graph is a function, giving the reason for your answer. b State the domain and the range. i -2 0 2 4 6 R 10 2 Explain their meaning in the context of the problem. e Write down the missing coordinate for each ordered pair from the graph: (0.2.). (0.8.).2). (2.). d State the temperature of the person at the start of the application. e After how many hours was the temperature of this person equal to 37°C? f During what period of time did the temperature of the person increase? Over what period did it decrease? • x-2r +1 8 642 o 4 6 8 c y--x+2 7 A special application measures the temperature of a person and records on a graph its variation from 37°C, considered to be the average optimum temperature. The application stops working when the temperature of the person is optimum. -2 -4 5 Determine whether these statements about the functions in question 4 are true or false. ai The point (-3, 2) lies on the graph of this function. i The image of x=-2 is y= 3. i When x-4, y= 0. bi The graph of this function crosses the X-axis at (-2, 0). -10 For a function f, the notation y fix) means that.x (an element of the domain, the input) is mapped through the function / to y (an element of the range, the output). 4 Find the domain and range of each of these functions. Note that: • fx) is read "f of x. • If y= fix) then x is said to be the independent variable and y is the dependent variable. • Different variables and names can be used for functions, such as d3Dvit), m= C(n), etc. HINT ii The point (o,-1) does not lie on the graph of this function. ii There is only one value of x for which y=-2. Be careful! fix) does not mean "f times.x. 216 217 Number and algebra Functions