Mathematics
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OpenStudy (anonymous):
The linear approximation at x = 0 to f(x) = \sqrt { 8 + 2 x } is y =
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OpenStudy (anonymous):
\[\sqrt{8+2x}\]
OpenStudy (coldplay):
x−−−−−
Its supposed to be the square root sign
\[\sqrt{8+2x}\]
OpenStudy (anonymous):
yes
OpenStudy (coldplay):
Got it.
OpenStudy (anonymous):
how
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OpenStudy (freckles):
Use the same formula from last time:
\[y=f(0)+f'(0)(x-0)\]
OpenStudy (anonymous):
so its 0?
OpenStudy (freckles):
what's 0?
OpenStudy (freckles):
\[f'(x)=?\]
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OpenStudy (anonymous):
i mean sqrt of 8
OpenStudy (freckles):
well f(0) is sqrt(8)
OpenStudy (anonymous):
so the derivative of that is 2?
OpenStudy (coldplay):
Yes.
OpenStudy (freckles):
\[y=f(0)+f'(0)(x-0) \\ y=\sqrt{8}+f'(0)(x-0) \\ y=\sqrt{8}+f'(0)x\]
The derivative of sqrt(8+2x) is not 2.
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OpenStudy (coldplay):
Oh wait no its not 2
OpenStudy (camper4834):
\[(8+2x)^\frac{ 1 }{ 2 }\] do this :)
OpenStudy (anonymous):
its (2x+8)^-1/2
OpenStudy (camper4834):
no manhani that negative exponent would make it a recipricol
OpenStudy (camper4834):
wait what?
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OpenStudy (anonymous):
thats the derivative of the equation tho
OpenStudy (camper4834):
XD yes yes sorry
OpenStudy (anonymous):
but when i plug in sqrt 8 + the derivative its saying its the wrong answer
OpenStudy (camper4834):
+ the derivative TIMES x
OpenStudy (camper4834):
did you forget the final x?
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OpenStudy (anonymous):
2.82+x((2x+8)^(-1/2)) its not going through
OpenStudy (camper4834):
which site are you using, sometimes they want it simplified a certain way
OpenStudy (anonymous):
webwork its for my homework
OpenStudy (perl):
The equation of the tangent line to f(x) at x = a is
L(x) = f(a) + f '(a) * ( x - a )
OpenStudy (camper4834):
\[\sqrt{8}+\frac{ x }{ \sqrt{8+2x} }\]
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OpenStudy (camper4834):
y = what is above
OpenStudy (camper4834):
try that and tell me what happens
OpenStudy (anonymous):
incorrect
OpenStudy (camper4834):
double check the equation you gave us then
OpenStudy (anonymous):
The linear approximation at x = 0 to f(x) = \sqrt { 8 + 2 x } is y =
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OpenStudy (anonymous):
did you multiply x?
OpenStudy (camper4834):
im stupid.... PLUG 0 INTO OUR DERIVATIVE!!
OpenStudy (camper4834):
(2*0+8)^-1/2
OpenStudy (anonymous):
i finally got it
OpenStudy (anonymous):
Thank you for your time!!
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OpenStudy (camper4834):
:)