- #1
quietrain
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- 2
Homework Statement
tan x = x
Homework Equations
The Attempt at a Solution
how do i solve this equation without using graphs?
is there a numerical method ?
thanks a lot!
try it and find out...quietrain said:er so how do i go about doing that?
draw a graph of y=tanx & y=x and pick an x value close to where they intersect, preferably on the left side of the intersection. Also notice there will actually be infinite solutions... so the value you start with will determine where you end upquietrain said:how do i know what to guess?
Close - more accuratly, we use a first order Taylor Series to construct the N-R method. For example, let the first order Taylor Series approximation for F(x), expanded about [itex]x_0[/itex], beso the gradient of the line in the form Y = MX + C ==> f(x0) - f(x1) = (x0 - x1) f '(x0)
so if i set f(x1) = 0, i will end up with the Newton-raphsod equation, which is the 1st order taylor series polynomial.
Yes! You got it. And yes, your function is [tex]F(x) = tan(x) - x[/itex]so is the term f(x1) equals 0 because i define my function tanx -x = 0? which means i am looking at the roots where tan x = x ?
so does it mean if my equation is tanx - x = 5, i must set my f(x1) term as 5? which means i am looking at the roots where tan x = 5+x?
so what the taylor series expansion does is actually like the Newton-raphsod method where you throw in your guess (x0) and it points you closer and closer to the actual value of f(x1)? from the equation f(x) ~ f(x0) + f'(x0)(x-x0)) + O(x^2)
If rather than until it converges. There is no guarantee that Newton-Raphson will converge. Consider the case g(x)=x1/3. Then g/g'=3x, making the Newton-Raphson iterator for finding a solution for g(x)=0 is xn+1=-2xb.TheoMcCloskey said:[tex]
x = x_0 -\frac{F(x_0)}{F'(x_0)}
[/tex]
We use this value of "x" and repeat the process (iterate) until convergence.
"Tan x = x" is a mathematical equation that represents the values of the tangent function and the variable x being equal to each other. In other words, it is an equation where the tangent of an angle is equal to the value of the angle itself.
A numerical method is used to solve "tan x = x" because it is a transcendental equation, meaning it cannot be solved algebraically. Therefore, a numerical approach, such as iteration or approximation, is needed to find an approximate solution.
The process for solving "tan x = x" using a numerical method involves choosing an initial guess for the solution, plugging it into the equation, and using a formula or algorithm to refine the guess until the solution is reached within a desired level of accuracy.
The accuracy of the solutions obtained through a numerical method for "tan x = x" depends on the chosen initial guess and the algorithm used. With a proper initial guess and a well-designed algorithm, the solutions can be very accurate.
Yes, there are limitations to using a numerical method to solve "tan x = x". These methods require a significant amount of computational power and can be time-consuming. Also, they may not always converge to a solution, especially if the equation has multiple solutions or a complex solution.