Determine the derivative, all the critical numbers and the intervals of increase and decrease
y=-5x²+20x+2

Question

Determine the derivative, all the critical numbers and the intervals of increase and decrease 
y=-5x²+20x+2

anonymous · Answer

$$\huge y'=-10x+20$$
$$\huge 0=-10x+20$$
$$x=2$$

anonymous · Answer

i get :
intervals of increase x<2
intervals of decrease x>2

but the answer key says the opposite

anonymous · Answer

when 
$$y \prime >0, $$
then increasing.

anonymous · Answer

what's in intervals of increase / decrease tho?

anonymous · Answer

I got the same answer as you @burhan101 
intervals of increase x<2
intervals of decrease x>2

anonymous · Answer

x>2 it decreases
x<2 it increases.

johnweldon1993 · Answer

Right...I as well @koymoi ...I think maybe your answer key is wrong @burhan101

anonymous · Answer

think the answer key's wrong then ?

dan815 · Answer

yes

anonymous · Answer

yeah, i thought it was a fairly straight forward question

dan815 · Answer

graph it and ull know for sure

dan815 · Answer

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