PRoblems with precalc functions

[crazy_shoes]

I'm trying to find where this function increases and decreases:

f(x) = = - x^2 - 6x - 8


I can get the vertex (h, k), which works out [by my math] to be (3, -17).

I'm just not sure where to go from here to get information like:
point of increase and decrease
domain and range

Thanks for any help!

 

[phoenixthoth]

For the vertex, I get (-3,1), using the formula for h=-b/(2a). The vertex is where it switches from increasing to decreasing or from decreasing to increasing. The leading coefficient tells you which of these two cases it actually is...

 

[crazy_shoes]

Aaah... I see what I did wrong, I simply forgot that a=-1, I was thinking a=1.

When I set a to -1 instead of 1 it all works out! Thanks!

 

[Ramzi]

hi,
i need help finding 2 solutions to an equation. cos(theta) = 1/(sq.root of 2)
thanks !

 

[Mark44]

hi,
i need help finding 2 solutions to an equation. cos(theta) = 1/(sq.root of 2)
thanks !

It's considered bad form to "hijack" an existing thread with a new question.

You should start a new thread.

 

[Ramzi]

im sorry ! its my first time using forums and all that stuff. my bad, but can anyone help me ?