# Thread: secant method to find root

1. ## secant method to find root

When i use secant method to do this question , I used 0 and 1 as my starting , however , i keep on getting 0 , here's my trial :

What's wrong with my working ?

2. ## Re: secant method to find root

I don't understand the question. Zero is a root of f(x) = x^2-sin(x), so what's the issue? The secant method will converge toward only one root given a pair of initial values for x1 and x2. To get the other root try using a different pair of initial values, say 0.8 and 1.0.

3. ## Re: secant method to find root

Hey xl5899.

Try looking at they graph and understand that you will have to go past the "bump" where the derivative is zero to converge to the second root.

4. ## Re: secant method to find root

Originally Posted by ChipB
I don't understand the question. Zero is a root of f(x) = x^2-sin(x), so what's the issue? The secant method will converge toward only one root given a pair of initial values for x1 and x2. To get the other root try using a different pair of initial values, say 0.8 and 1.0.
here's what i gt when i use 0 and 1 as starting
i keep on getting 0

5. ## Re: secant method to find root

Read posts 2 and 3. You can NOT use 0 and 1 as your starting values because 0 is too close to the other root (in fact, it IS the other root). You need to choose a point PAST the turning point!