Question

What is the x-intercept of y = 3x² + 6x + 3 ?
o
1
-1
3

Answer 1

Therefore the x-intercept of

`y=3x^(2)+6x+3`

is

`x=-1`

Explanation:

Intercepts:

The line which intersect on x-axis and y-axis are called intercepts.

There are two intercepts:

y-intercept: The line which intersect at y-axis. So when the line intersect at y-axis X coordinate is zero.

x-intercept: The line which intersect at x-axis. So when the line intersect at x-axis Y coordinate is zero.

For x-intercept of y = 3x² + 6x + 3

put y = 0

`0=3x^(2)+6x+3`

Dividing throughout by 3 we get

`0=x^(2)+2x+1`

`0=x^(2)+2* 1* x+1^(2)`

Which is nothing but in the identity form of (A+B)² = A² +2AB +B²

A = x

B = 1

Therefore Equation becomes

`(x+1)^(2)=0\\x+1=0\\x=-1`

Therefore the x-intercept of

`y=3x^(2)+6x+3`

is

`x=-1`