Will pay $10 through paypal for the correct answer. See attached file in the comments.
the file isnt attached. :o
I think I know how to do two of the questions. But I'm really not sure. And I don't want to find out after it's been graded...
umm, sorry i can't help u with these.. but i know people who can help.. but u have to wait for a couple of hours for them.. this site is free to use, people help u for free, no dont use the paypal thing. LOL try asking, satellite, myininya, zarkon, a.msitre etc.
Damn, okay... And those people aren't on at the moment? Thanks for trying.
No they aren't.. but they will be in some hours...
i know that nCr formula.. but i used that in binomial expansion!
Hoodrych, do you know how to do a linear approximation?
Yeah, somewhat. We've learned it. That's what it is over.
What are you using to graph? (calculator, software, etc?)
I shouldn't need one..
Let's say they wanted you to approximate \(f(x) = \sin(x)\) using a linear \(L(x)\) and quadratic \(Q(x)\) approximation at \(x=0\). First make a table of derivatives for the functions like this: \[\begin{cases}f(x) &= \sin(x)\\ f'(x) &= \cos(x)\\ f''(x) &= -\sin(x)\end{cases}\] Then make a table of derivatives for the LINEAR approximation like this: \[\begin{cases}L(x) &= Ax + B\\ L'(x) &= A\end{cases}\] Then make a table of derivatives for the QUADRATIC approximations like this: \[\begin{cases}Q(x) &= Ax^2 +Bx +C\\Q'(x) &= 2Ax + B\\Q''(x) &= 2A\end{cases}\] Then EVALUATE the function at the given point \(x=0\) \[\begin{cases}f(0) &= \sin(0) & = 0\\ f'(0) &= \cos(0) &= 1\\ f''(0) &= -\sin(0) &= 0\end{cases}\] Then EVALUATE the QUADRATIC approx at the given point \(x=0\) \[\begin{cases}Q(0) &= A(0)^2+B(0)+C &= C\\ Q'(0) &=2A(0)+B &= B \\ Q''(0) &= 2A &=2A \end{cases}\] Then EVALUATE the LINEAR approx at the given point \(x=0\). \[\begin{cases}L(0) &= A(0) + B & = B \\ L'(0) & = B & = B \end{cases}\] Now we match up the coefficients. Let's do this for the Quadratic approximation first. \[\begin{cases}f(0) = 0 = Q(0) = C\\ f'(0) = 1 = Q'(0) = B \\ f''(0) = 0 = Q''(0) = 2A\end{cases}\] Hopefully it is obvious that \(C = 0, B = 1, \text{ and } A = 0\) which means our QUADRATIC approximation to \(f(x) = \sin(x)\) at \(x=0\) is \(Q(x) = x\) (because \(Q(x) = Ax^2 + Bx +C\) ) Do the same thing for the linear approxmation! :)
I think you messed up on the Linear approximation. L(x) should be, L(x) = f(a)+f '(a)(x-a)
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