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Clarence
 one year ago
"Assume that the graph of the polynomial p(x)=ax2+bx+cpasses through the point (−1,2)and has a horizontal tangent at (12,−9). Find the sum a+b+c."
I've already substitute (1, 2) into the polynomial equation to get a  b + c = 2 and differentiate the original polynomial to get 2ax+b=0 and replaced x with 12 to get 24a + b = 0 as well as utilizing (12, 9) to get 144a + 12 b + c = 9 but I have no idea where to go from there..
Clarence
 one year ago
"Assume that the graph of the polynomial p(x)=ax2+bx+cpasses through the point (−1,2)and has a horizontal tangent at (12,−9). Find the sum a+b+c." I've already substitute (1, 2) into the polynomial equation to get a  b + c = 2 and differentiate the original polynomial to get 2ax+b=0 and replaced x with 12 to get 24a + b = 0 as well as utilizing (12, 9) to get 144a + 12 b + c = 9 but I have no idea where to go from there..

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asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0your steps are correct so far

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0you now have 3 equations with 3 unknowns

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0solve these to find a, b and c and then calculate a+b+c

clarence
 one year ago
Best ResponseYou've already chosen the best response.2I've tried to use row operations but was unsuccessful, is there a particular order that I should place these equations?

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0You could just use simple substitution, e.g. start by eliminating c using the last equation

clarence
 one year ago
Best ResponseYou've already chosen the best response.2I'm not quite sure I understand you, use 144a + 12b + c = 9 to eliminate c?

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0c = 9 12b 144a from that equation now substitute this into your first equation

clarence
 one year ago
Best ResponseYou've already chosen the best response.2Oh, the ab+c=2 equation?

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0you will then be left with 2 equations in two unknowns  a and b

clarence
 one year ago
Best ResponseYou've already chosen the best response.2How does that help? I have 13b143a=11 right now.

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0and you also have: 24a + b = 0

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0which gives you: b = 24a substitute that into: 13b143a=11 and solve for a

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok what do you need help with, solving for a?

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0not quite  you must have made a simple algebraic mistake

clarence
 one year ago
Best ResponseYou've already chosen the best response.2Did you not get 312a143a=2?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.013b143a=11 13(24a)  143 a = 11 312a  143a = 11 169a = 11 /169 on both sides a = 11/169

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0remember the negative sign

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0I am talking to @Clarence

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok sorry just trying to help

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0now you are just left with c to calculate and then you can work out what a+b+c equals

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0wow sounds like you got it down, now just add them together

clarence
 one year ago
Best ResponseYou've already chosen the best response.2So all together it'd be 190/169?

clarence
 one year ago
Best ResponseYou've already chosen the best response.2Oh I get it now, thanks!

asnaseer
 one year ago
Best ResponseYou've already chosen the best response.0why do I feel like there is an echo in here :)

clarence
 one year ago
Best ResponseYou've already chosen the best response.2Probably because there is ;) Thanks again guys/girls!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0haha you keep typing and replying right before i do and i don't see it sorry
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