Question

The graph shows a function.
Find the value of b and d.

Answer 1

The required values are b=-6 and d=4

Explanation:

The graph corresponds to the function

`r(x) =x^2+bx^2+8x+d`

We are required to find the values of b and d.

They can be found by using two points that are clearly visible on the graph. For example, the points (0,4) and (2,0) belong to the function. Substituting their values in the function:

`4 =0^2+b*0^2+8*0+d`

Simplifying:

4 = d

d = 4

Now use the point (2,0):

`0 =2^2+b*2^2+8*2+d`

Since d=4, and calculating

`0 =4+4b+16+4`

Simplifying:

`4b = -24`

Dividing by 4:

`b = -24/4 = -6`

`b = -6`

The required values are b=-6 and d=4