Parabola,maths jee , class
11.
What is the equation of the axis of symmetry of the parabola given by the equation y = 6(x + 1)(x -
5)?
a. y = 2
b. x = -2
c. y = -2
d. x = 2
Explanation
The axis of symmetry lies directly between the two roots. You can find it on a graph by working your
way to the middle or algebraically by calculating the average between the two points:
x = (p + q)/2.
For y = 6(x + 1)(x - 5)
To find p and q, remember to change the sign of each number. (Think of it as (x + 1 = 0). Therefore x
= -1 and (x - 5 = 0) (Thus, x = 5)
p = -1
q=5
x = (-1 + 5)/2
x=2
11.
What is the equation of the axis of symmetry of the parabola given by the equation y = 6(x + 1)(x -
5)?
a. y = 2
b. x = -2
c. y = -2
d. x = 2
Explanation
The axis of symmetry lies directly between the two roots. You can find it on a graph by working your
way to the middle or algebraically by calculating the average between the two points:
x = (p + q)/2.
For y = 6(x + 1)(x - 5)
To find p and q, remember to change the sign of each number. (Think of it as (x + 1 = 0). Therefore x
= -1 and (x - 5 = 0) (Thus, x = 5)
p = -1
q=5
x = (-1 + 5)/2
x=2
