Question

The line of symmetry for the quadratic equation y = ax2 - 2x - 3 is x = 1. What is the value of "a"?

Answer 1

value of a is 1.

Explanation:

A quadratic equation
`y=ax^2+bx+c` ....[1] where a, b and c are the coefficient.

then the axis of symmetry is given by:

`x = -(b)/(2a)` .....[2]

As per the statement:

The line of symmetry for the quadratic equation
`y = ax^2-2x -3` is x = 1.

On comparing given quadratic equation with [1] we have;

b = -2

then;

Substitute x = 1 in [2] we have;

`1= -(-2)/(2a)`

Simplify:

`1 = (1)/(a)`

⇒
`a = 1`

Therefore, the value of a is 1.