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?
- x = 1
- x = -1
-
y = 1
- y = -1
- x + y = 1
The correct answer is: 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