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anonymous
 one year ago
Find the coefficient of the squared term in the simplified form for the second derivative., f"(x) for f(x)=(X^3+2x+3)(3x^36x^28x+1). use the hyphen symbol,, for negative values.
anonymous
 one year ago
Find the coefficient of the squared term in the simplified form for the second derivative., f"(x) for f(x)=(X^3+2x+3)(3x^36x^28x+1). use the hyphen symbol,, for negative values.

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zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4Hey Maggy :)\[\large\rm f(x)=(x^3+2x+3)(3x^36x^28x+1)\]Hmm this one looks like a doozy. Remember your product rule?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4\[\rm \color{royalblue}{f'(x)}=\color{royalblue}{(x^3+2x+3)'}(3x^36x^28x+1)+(x^3+2x+3)\color{royalblue}{(3x^36x^28x+1)'}\]This is how we would "set up" our first derivative, ya? :d

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4Alternatively, you could expand out all the brackets from the start. That might actually be easier :) Hmm I'm not sure.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4ya ya ya ya, expand first. that seems way better >.< Otherwise we have to combine a whole lot of term at the end.. my bad

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4we allowed to do that, ya? :d

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0my head hurts trying to follow you lol so we expand?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4ya let's try that instead :) product rule will result in two groups of stuff. second derivative will require product rule twice more. then expanding three sets of things, and combining. expanding first seems way simpler

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4Here is the expansion of the first two terms from the first set of brackets multiplying everything in the other brackets. Does it kinda make sense what I'm doing? :d there is one more term to take care of.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0yes I see you expanding to dind the derivatives. o.o math is not my forte lol

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4dw:1438994231877:dwwe have another set of terms to get. so we'll have to distribute this 3.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4We're going to take two derivatives. If we want to END UP WITH a second power. which power of x do you think we'll be starting with? :)

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4when we take the derivative of a third power such as that term, we'll get a second power. when we take the derivative again, it degrades down to first power, ya?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4So it looks like we'll want to pay attention to the `fourth power` term. That is the one which becomes `second power` after differentiating it twice.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4You `could` take the derivative of the entire thing. But it doesn't look the problem is requiring that, if I'm reading it correctly. They simply want the coefficient on the 2nd power term in your second derivative. So we currently have 2x^4. What do you get when you differentiate 2x^4 twice?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.02x^8??? ( when you say twice you mean add or multiply im getting very confused)

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4\(\large\rm (2x^4)'=?\)

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4Remember your power rule? :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0sorta but not confidently

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4\(\large\rm (x^n)'=n x^{n1}\) The exponent comes down in front to multiply, and the exponent decreases by 1.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4Example: \(\large\rm (4x^7)'=4\cdot7x^{71}=28x^{6}\) See how the 7 comes down in front, and the power changes to a 6?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so it be 2x^3? from 2x^4?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4Nooo :O Where did your 4 go? it didn't come down silly!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I cant see your last posted picture that wy I ask my answer was right lol all I see in your last picture posst is symbols

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4oh the math code didn't format correctly :( ugh

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4This was the example:dw:1438995007902:dw

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4The 7 comes down, and then the power decreases to a 6.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.08x^3? my reasoning: 2x^4= 2. 4x^3 = 8x3

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4Oo ok nice nice nice. That takes care of our first derivative. Now we have to repeat the process! :)dw:1438995233431:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.08x^3 8x^3=8.3x^2=24x^2?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4Yayyy good job \c:/ Notice that the exponent we started with was a 4. And the one we ended with is a 2. Differentiating twice made the power decrease by 2. That will happen to every other term as well. So our 5th power term will becomes a 3rd power, our 3rd power term will become a 1st power, and so on. So we only needed to differentiate the 4th power term twice, because that's the only one giving us 2nd power!

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4So yay good, you've found your coefficient! :) 24

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok so my answer to my question is 24x^2?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4The question said `Find the coefficient`. The coefficient is `only` the number in front.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0oh coolz hehe can you help me in one more question?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.4bahh i need a maf break :) open up a new thread so people can find your question faster! this one is a mess now hehe
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