Question

cm
Q18. A student was given the task to prepare a graph of quadratic polynomial f(x). To draw
this graph he take several values of y corresponding to different values of x. After
plotting the points on the graph paper with suitable scale, he obtain the graph as shown
below :-
4-
y = f(x)
3
2
1 (0, 1)
(10)
(3,0)
3
-1-1
2
34
Based on the above graph answer the following questions :-
(i) The graph of quadratic polynomial intersects X=axis :-
(a) at least at two points
(b) atmost at two points
(c) exactly one point
none of these
(11)
The zeroes of the polynomial are the x-coordinates of those points :-
а)
where their graph touch or intersect the X-axis.
(b)
where their graph touch or intersect the Y=axis.
(c)
where their graph touch or intersect both axs.
(d) none of these
4​

Answer 1

Answer:

answer is below my questioner.and d is answer.

Step-by-step explanation:

Let y =f(x) or, y=3−2x−x

2

.

Let us list a few values of y=3−2x−x

2

corresponding to a few values of x as follows

x −5 −4 −3 −2 −1 0 1 2 3/4

y=3−2x−x

2

−12 −5 0 3 4 3 0 −5 −12/−21

Thus, the. following points lie on the graph of the polynomial y=3−2x−x

2

(−5,−12),(−4,−5),(−3,0),(−2,3),(−1,4),(0,3),(1,0),(2,−5),(3,−12) and (4,−21).

Let plot these points on a graph paper and draw a smooth free hand curve passing through these points to obtain the graphs of y=3−2x−x

2

. The curve thus obtained represents a parabola, as shown in figure. The highest point P (−1,3), is called a maximum points, is the vertex of the parabola. Vertical line through P is the axis of the parabola. Clearly, parabola is symmetric about the axis.