draw the graph for the equation x^2+2x-3=0
Answers
Step-by-step explanation:
Let us draw the graph of y=x
2
−2x−3.
Now, form the following table by assigning integer values from −3 to 4 for x and finding the corresponding values of y=x
2
−2x−3.
x −3 −2 −1 0 1 2 3 4
x
2
9 4 1 0 1 4 9 16
−2x 6 4 2 0 −2 −4 −6 −8
−3 −3 −3 −3 −3 −3 −3 −3 −3
y 12 5 0 −3 −4 −3 0 5
Plot the points (−3,12),(−2,5),(−1,0),(0,−3),(1,−4),(2,−3),(3,0),(4,5) and join the points by a smooth curve.
The curve intersects the x-axis at the points (−1,0) and (3,0)
The x-coordinates of the above points are −1 and 3
Hence, the solution set is {−1,3}.
Note
(i) On the x-axis, y=0 always.
(ii) The values of y are both positive and negative. Thus, the curve lies below and above the x-axis.
(iii) The curve is symmetric about the line x=1. (It is not symmetric about the y-axis)
solution