Find the intervals on which y = (x +4)^2 - 7 is increasing or decreasing
I have never had a problem like this i don't know what to do please help
thank you!
Actually there's a quicker way. A (vertical) parabola has the form:
$\displaystyle y = a(x - h)^2 + k$
where the vertex is at (h, k) and it opens upward if a > 0 and opens downward if a < 0.
So the vertex of $\displaystyle y = (x + 4)^2 - 7$ is at (-4, -7) and a = 1. Thus it opens upward. So it must be decreasing on $\displaystyle ( - \infty, -4)$ and increasing on $\displaystyle (-4, \infty)$.
-Dan