Question

5. Identify the following for the quadratic relations shown. 2 3 a) co-ordinates of the vertex b) y intercept c) maximum or minimum value -20 16 12 - 20 0 6. The graph below shows the height, in meters, of a diver jumping off a springboard versus time, in seconds. a) What is the initial height of the jumper? What is this called in math terminology? b) What is the vertex? What do these numbers represent for this dive? c) What is the x intercept? What does this number represent for this dive? 7.

Answer 1

5. f(x) =ax^2+bx+c is the quadratic equation. If a>0 then f(x) has minimum and if a<0 then f(x) has maximum.

In first graph 1) f(x) has a>0 i.e. has minimum and the coordinates of this point are the coordinates of vertex , i.e. (1,2)

y-intercept is where x=0 and hence is y=4.

At x=1, minimum value is y=2.

Graph 2) f(x) has minimum at x= -1 and the minimum value y is -4. Y-intercept is -3.

Graph 3) f(x) has minimum at x= 1 and the minimum value y is 2 . Y-intercept is 4.

Graph 4) f(x) has maximum value at x= 3 , the maximum value y is 18, y-intercept is 0