Functions?

[Nerdie]

I think this is from AlgII/Trig last year (I'm in Analysis now) and I remember how to solve function when they give you an f(x)=blablabla and f(2 (or any #) =?................. but we were given a review HW.... and I can't figure out how to plug stuff in given the wording... or rather numbering Not trying to get answers offline... and it's really simple stuff.... just need some help to get started (I don't know what to plug in where) :


Given f(x)= 4x + 5 and h(x)= x^2 + 5x - 24...

Solve:

f(x) = g(x)
g(x) is less than or equal to 0


Thank you so much!

 

[Deleted member 4993]

I think this is from AlgII/Trig last year (I'm in Analysis now) and I remember how to solve function when they give you an f(x)=blablabla and f(2 (or any #) =?................. but we were given a review HW.... and I can't figure out how to plug stuff in given the wording... or rather numbering Not trying to get answers offline... and it's really simple stuff.... just need some help to get started (I don't know what to plug in where) :


Given f(x)= 4x + 5 and h(x)= x^2 + 5x - 24...

Solve: (in these problems "solve" means "Find the value of x when:")

f(x) = 0 → 4x + 5 = 0 → 4x = -5 → x = -5/4

f(x) = g(x) .... Your turn!

g(x) is less than or equal to 0
f(x)= 13
f(x) > 0

Thank you so much!

Please share your work with us, indicating exactly where you are stuck - so that we may know where to begin to help you.

 

[Nerdie]

Please share your work with us, indicating exactly where you are stuck - so that we may know where to begin to help you.

Thank you! Now when I get to f(x) = h(x) I'm stuck.

4x + 5 = x^2 + 5x -24
0 = x^2 + x - 29

Then do I complete the square? Or how do I solve that? Did I take the right step?

 

[Deleted member 4993]

Thank you! Now when I get to f(x) = h(x) I'm stuck.

4x + 5 = x^2 + 5x -24
0 = x^2 + x - 29

Then do I complete the square? Or how do I solve that? Did I take the right step?

Correct.

Now use quadratic formula to solve for 'x'.

Completing the square won't work here elegantly.

 

[Nerdie]

Correct.

Now use quadratic formula to solve for 'x'.

Completing the square won't work here elegantly.

Perfect! Thank you so much !