Question

How do you find the y-intercept of `y = x^2 + 6x + 9`?

Answer 1

y-intercept `=9`

Explanation:

The y-intercept is the value on the Y-axis where the equation crosses the Y-axis.

Since `x=0` for all point on the Y-axis
another way to say this is that:
the y-intercept is the value of `y` when `x=0`

Given `y=x^2+6x+9`

when `x=0`
`color(white)("XXX")y=0^2+6xx0+9 = 9`

graph{x^2+6x+9 [-16.21, 12.27, -0.37, 13.87]}