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onegirl
Group Title
Find an equation of the tangent line to y = f(x) at x = 1. f(x) 3e^x
 one year ago
 one year ago
onegirl Group Title
Find an equation of the tangent line to y = f(x) at x = 1. f(x) 3e^x
 one year ago
 one year ago

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onegirl Group TitleBest ResponseYou've already chosen the best response.0
@zepdrix hi can u help for a minute i know how to do this since you showed me yesterday how..but i'm stuck on something, so can u help?
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
@Mertsj can u help?
 one year ago

zepdrix Group TitleBest ResponseYou've already chosen the best response.1
sup? c: what part confusing you?
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
okay so i tried doing this one here is what i got so far i found the derivative of 3e^x and i got d/dx (3e^x) = 3(d/dx (e^x)) = 3e^x so now I filled in the 1 into 3e^x and I got 3e so i want to put it into y=mx + b and i got stuck there
 one year ago

zepdrix Group TitleBest ResponseYou've already chosen the best response.1
Yah it's a weird looking number, so I can see how it's a little confusing. So you calculated the slope, \(\large m\). \(\large m=3e \qquad \rightarrow \qquad y=(3e)x+b\)
 one year ago

zepdrix Group TitleBest ResponseYou've already chosen the best response.1
To solve for \(\large b\) remember that we needed a coordinate pair that we could plug into this. Where can we get a coordinate pair from? :o
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
hmmm 1 in the original question that would be our x and for y we would put 1 into 3e^x
 one year ago

zepdrix Group TitleBest ResponseYou've already chosen the best response.1
k sounds good.
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
okay so our coordiantes will be (1, 3e) ? since when you plug in 1 into 3e^1 you get 3e
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
so 1 = (3e)x + b ?
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
wait i meant 1 = 3e(1) + b
 one year ago

zepdrix Group TitleBest ResponseYou've already chosen the best response.1
\[\huge \left(\color{orangered}{x},\;\color{royalblue}{y}\right) \qquad = \qquad \left(\color{orangered}{1},\;\color{royalblue}{3e}\right)\]Plug those into here,\[\huge \color{royalblue}{y}=(3e)\color{orangered}{x}+b\] You didn't quite get them plugged in correctly. Maybe the colors will help you match them up.
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
ohhh okay hold on
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
so 3e = 3e(1) + b?
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
okay then i solve for be and i'm done right?
 one year ago

zepdrix Group TitleBest ResponseYou've already chosen the best response.1
Yes, solve for b. Then rewrite your final equatoin with y, x, m and b. Good job c:
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
so i fot 3e = 3e(1) + 0
 one year ago

zepdrix Group TitleBest ResponseYou've already chosen the best response.1
yes, but you want to write it as an equation involving x and y. We no longer want the coordinate pair plugged in for our final answer.
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
ok how would i do that?
 one year ago

zepdrix Group TitleBest ResponseYou've already chosen the best response.1
Remember we were trying to come up with an equation for the tangent line. It will be of the form \(\large y=mx+b\). We ONLY want to fill in the missing \(\large m\) and \(\large b\). We had plugged in our coordinate pair to help us find \(\large b\), but now we don't need that coordinate pair.
 one year ago

zepdrix Group TitleBest ResponseYou've already chosen the best response.1
x=x y=y :d
 one year ago
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