A student told to draw the graph of y = x2 + 4x – 6. He is then told to draw a liner graph on the same axis such that the intersection of the two graphs will give the solutions to the equation x2 + 4x – 7 = 0, What is the equation of the linear graph he needs to draw?
-
A.
x = 1 -
B.
x = -1 -
C.
y = 1 -
D.
y = -1 -
E.
x + y = 1
Correct Answer: Option C
Explanation
The linear equation will be the difference between the equation.
y=x2 + 4x – 6 and x2 + 4x – 7 = 0
y=x2 + 4x – 6, ( 0 = x2 + 4x – 7)
y = -(-1) y = 1