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 2 years ago
where is everyone?!? help please! =(
find the extrema: 4x^313x^2+4x+1
max and min:
[1,4]
[0,2]
 2 years ago
where is everyone?!? help please! =( find the extrema: 4x^313x^2+4x+1 max and min: [1,4] [0,2]

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mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0so i found the derivative: 12x^2 26x +4

heradog
 2 years ago
Best ResponseYou've already chosen the best response.1I could maybe figure it out for myself on my calculator but I don't know how that would help, are you in webworks?

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0do you know hot to factor: 12x^2 26x +4

heradog
 2 years ago
Best ResponseYou've already chosen the best response.1I'll try and see if I can help but can't promise so yeah you have the derivative right

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0not on calculator though... i just need to know just in case.

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0i must factor first in order to = to 0

heradog
 2 years ago
Best ResponseYou've already chosen the best response.1so to find max and min you find the derivative set it = to 0 and solve?

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0yes i have to find the critical points.. then evaluate the point to original function

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0then evaluate with the endpoints. then i'll find max and min

heradog
 2 years ago
Best ResponseYou've already chosen the best response.1so you have 1/6 and 2 for the critical points right?

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0@campbell_st @precal @heradog the more help the better! :( i really need to figure this problem out.

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0well.... i don't know how to factor this exactly: 12x^2 26x +4

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0since derivative is right... then how do i factor it out?

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0yes @precal that one is right

heradog
 2 years ago
Best ResponseYou've already chosen the best response.1ok so to factor you pull out the recurring elements I so suck at factoring but lets try it you can multiply every element by 2 giving you 2(6x^213x+2)

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0hm... i did that also... but then i have to find x . critical points.

precal
 2 years ago
Best ResponseYou've already chosen the best response.1are you given those intervals? [1,4] and [0,2]

campbell_st
 2 years ago
Best ResponseYou've already chosen the best response.0the stationary points are at (x  2)(12x 2) = 0 so the stationary points are x = 2, x = 1/6 so find the the 2nd derivative and test them for max and min then check you boundary values... an easy way it to graph the curve

precal
 2 years ago
Best ResponseYou've already chosen the best response.1why not just do a sign analysis with the first d/dx, second d/dx states concave up or concave down doesn't 1st d/dx show max and min

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0kindly, can we stick with these steps.... {Differentiate} {Set f '(x) = 0} {Factor} {solve to get the critical numbers}

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0im already used to them...

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0@precal what did you do after 2(6x^213x+2) ? i dont understand how you got the x^2....etc after...

precal
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1363327620907:dwit is an old jedi trick called slide and divide, makes factoring easier to do

campbell_st
 2 years ago
Best ResponseYou've already chosen the best response.0the attached image may help

precal
 2 years ago
Best ResponseYou've already chosen the best response.1max at x=1/6 and min at x=2

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1363327660835:dw

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0what i meant t say how? i know you said a trick way but i don't know how... :/

campbell_st
 2 years ago
Best ResponseYou've already chosen the best response.0the 2nd derivative test is used for determining if the point is a max or min... easier than 1st der and change of sign...

precal
 2 years ago
Best ResponseYou've already chosen the best response.1true but if this is for a calculus ab class, they are taught to do 1st d/dx to determine max and min

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0stilll dont understand .. :(

precal
 2 years ago
Best ResponseYou've already chosen the best response.1just factor using whatever technique or strategy you were taught, factoring is a basic skill you will need to for future math courses. I just used a technique I like that helps me factor faster......

campbell_st
 2 years ago
Best ResponseYou've already chosen the best response.0ok... here is how I factor it and it works every time given \[ax^2 + bx + c = 0\] multiply a by c in your question 6 times 2 = 12 find the factors of 12 that add to 13....12, 1 then you have (ax + factor1)(ax + factor 2) (6x 12)(6x 1)   = 0 a 6 find the common factors in the numerator 6(x 2)(6x 1) = 0  6 cancel the common factors leaves (x 2)(6x 1) = 0 easy to solve

precal
 2 years ago
Best ResponseYou've already chosen the best response.1like I said earlier, use whatever works for you. This problem is beyond factoring......

precal
 2 years ago
Best ResponseYou've already chosen the best response.1kindly, can we stick with these steps.... {Differentiate} {Set f '(x) = 0} {Factor} {solve to get the critical numbers} btw I did utilize the steps above

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0yes i used that too. i mea im fine with everything except factoring now.

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0i know it was a basic thing we have to know but i forgot. so I'm trying to find an easy way to learn.

precal
 2 years ago
Best ResponseYou've already chosen the best response.1well I like to use slide and divide

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0i never used that technique before

precal
 2 years ago
Best ResponseYou've already chosen the best response.1look it up, you will find many videos on it on youtube. good luck. factoring gets easier over time.

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0i put the answer: [1,4] max=65 min= 11 and for [0,2] max= 196 min= 11 what's wrong with the answer?

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0somebody help pls!

precal
 2 years ago
Best ResponseYou've already chosen the best response.1are you looking for absolute max or absolute min? are you looking for global or local max or min? seems like you are doing something else other than looking for critical numbers

precal
 2 years ago
Best ResponseYou've already chosen the best response.1gotta go will help you tomorrow, it is very late for me at the moment (past 2 am)
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