Question

# Draw the graphs of the quadratic polynomial f(x)=3-2x -x?

Solution

Let y= f(x) or, y=3 - 2x - x2
Let us list a few values of y=3 - 2x - x2 corresponding to a
few values of x as follows:
Ix - 4-2-10/1 2 3 4
y=3-2x-x² -12 5 3 4 3 0 5 -12 | 21 |
Thus, the following points lie on the graph of polynomial
y=3- 2x - x2:
(-5, -12), (-4,-5),(-3,0),(-2,3), (-1,4),(0,3), (1,0), (2,-5),
(3,-12) and (4, -21)
Let us plot these points on a graph paper and draw a smooth
free hand curve passing through these points to obtain the
graph of y=3 - 2x - x2. The curve thus obtained represents
a parabola, as shown in figure.
TOSIN