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anonymous
 5 years ago
The function y=x^4 + bx^2 + 8x + 1 has a horizontal tangent and a point of inflection for the same value of x. What must be the value of b?
anonymous
 5 years ago
The function y=x^4 + bx^2 + 8x + 1 has a horizontal tangent and a point of inflection for the same value of x. What must be the value of b?

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myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0is b the yintercept?

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0i dont know if that will help us lets see what heppens

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0oh wait erase that we have 2 equations right the one with y' and the one with y'' set both = to zero so y'' gives us 12x^2+2b=0 which means b=12x^2/2=6x^2 so take y' which gives us 4x^2+2bx+8=0 and where you see that x plug in 6x^2

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0so we have 4x^3+2(6x^2)x+8=0 4x^312x^3+8=0 8x^3+8=0 and so on...

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0you did see the typo above right when i wrote 4x^2 its suppose to be 4x^3

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Yea lol! I'm going to see what I get!

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0so anyways we have 8x^3=8 so x^3=1 so x=1

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0if x=1 and b=6x^2, then what does b=__

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0b=6 and that's what the answer says!! :D

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0did you understand the steps? do you want me to say why i did something or do you got it? this was a nice problem

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I understand! Yea it was a nice problem indeed!

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0i seen another typo way up there it says replace c with 6x^2 thats suppose to be replace b with 6x^2 i cant type im sorry

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0You were probably typing fast but yea I understand! Thanks!
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