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anonymous
 5 years ago
Can anyone find the tangent line approximation for f(x)=x^4+3x^2, when
a =1?
anonymous
 5 years ago
Can anyone find the tangent line approximation for f(x)=x^4+3x^2, when a =1?

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myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0f '(x)=4x^3+6x did you get this far?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok i know how you got there

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.010 is the slope of the tangent line at x=1

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0so we know a point on the line and we know the slope of that line and a line has form y=mx+b f(1)=10(1)+b we can find b now 1+3=10+b 4=10+b 10+4=b 14=b so the tangent line is y=10x+14

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0For whatever reason the answers in the back of the book are telling me the tangent would equal 10x6, is it possible we mixed signs along the way?

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0let me do it on paper one sec

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0is this what you are confused about? the answer in the back of the book? did you try this problem and get what I got?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0You didn't plug in 1

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0No i got something like x^5+5x^4+7x^3+9x^2+6x because i thought it was F(x)=f(a)+f'(a)(xa) inorder to solve this beast

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0y=10x+b we need to know b we know a point on this line

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Nah, just find the slope of the tangent and plug in that slope into point slope formula

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Ok after you get the slope of the tangent what did you plug in to get you (x,y) values?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\(x = 1 \implies f = x^4+3x^2 = ?\)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0thats 4 but we are stillnot jiving with the stupid books answer

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0so we have y=10x+b 4=10(1)+b

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Take the slope (10) and the point (1,4) and plug into point slope. \(yy_0 = m(xx_0)\)

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0you can use either way

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Where m is the slope, \(x_0,y_0\) are the x and y for your point.

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0b=410=6 so y=10x6

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I like point slope cause I don't have to do anything else. Slope intercept is only useful if you're gonna graph it.

myininaya
 5 years ago
Best ResponseYou've already chosen the best response.0i like slope intercept its more fun to me for some reason

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Ok where did we pull the y value from (4) sorry i missed how we came up with that one

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Plug in x=1 to the original equation for f(x)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Nevermind I'm sorry, I just figured that part out, thanks for the help guys. It has been a long day to put it nicely.
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