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deepthiakella1
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identify the open intervals on which the function is increasing or decreasing f(x)=(x+3)^3
 9 months ago
 9 months ago
deepthiakella1 Group Title
identify the open intervals on which the function is increasing or decreasing f(x)=(x+3)^3
 9 months ago
 9 months ago

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tkhunny Group TitleBest ResponseYou've already chosen the best response.0
Do we get to use the derivative?
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
yup!
 9 months ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.0
Allrighty, then. Show us f'(x).
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
3(x+1)^2
 9 months ago

shamil98 Group TitleBest ResponseYou've already chosen the best response.0
the derivative is 3(x+3)^2
 9 months ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.0
Perfect. If you think of the right thing, the answer to the following question is really, REALLY easy. :) Where is f'(x) negative, given that \(f'(x) = 2(x+3)^{2}\)?
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
wait did i get the derivative wrong
 9 months ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.0
No, you got it. I just had a typospasm. The answer to my question is the same. When is f'(x) negative? Don't look at the graph. Just think on the structure. A Real Number squared. When is that negative?
 9 months ago

shamil98 Group TitleBest ResponseYou've already chosen the best response.0
I got a question, why is 3(x+3)^2 not the derivative? o.o
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
Isnt it using the chain rule...maybe haha
 9 months ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.0
?? Why as that? You have it. Don't let my typo confuse you. \(f(x) = (x+3)^{3}\) \(f'(x) = 3(x+3)^{2}\) Okay, now answer... When is f'(x) negative?
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
so actually my question was f(x)=(x+1)^3 but thats okay haha but im not sure it can be negative
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
idk
 9 months ago

shamil98 Group TitleBest ResponseYou've already chosen the best response.0
oh then the derivative is 3(x+1)^2
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
hahaha ya
 9 months ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.0
Come on. You can see it. If you start with a Real Number, and Square it, will you EVER get a negative number? The derivative is NOT \(3(x+1)^{2}\). The derivative is \(f'(x) = 3(x+1)^{2}\). Don't be afraid to write whole, complete expressions.
 9 months ago

shamil98 Group TitleBest ResponseYou've already chosen the best response.0
sorry, f'(x) = 3(x+1)^2 continue with your explanation :P
 9 months ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.0
Can f'(x) EVER be zero (0)?
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
if x was 1 right?
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
haha im stupid at calc. sorry :(
 9 months ago

deepthiakella1 Group TitleBest ResponseYou've already chosen the best response.0
tkhunny where did you go????
 9 months ago
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