# urgent HW help

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• Dec 29th 2008, 03:19 AM
ea12345
urgent HW help
Q.1 Use Newton’s method to find the value of x for the function
f(x)=2x^2+4x-3=0 ; x>0

Note: Perform only 3 iterations.

Q2 and Q3 in attachment

thanks in advance
• Dec 29th 2008, 03:41 AM
Grandad
Various problems
Hello
Quote:

Originally Posted by ea12345
Q.1 Use Newton’s method to find the value of x for the function
f(x)=2x^2+4x-3=0 ; x>0

Note: Perform only 3 iterations.

Q2 and Q3 in attachment

thanks in advance

You don't say where the problems lie, so I'll just give you some general hints.

1 $f'(x)=4x+4$

Try, say, $x_1=1$ as a first approximation, and then use

$x_{n+1} = x_n-\frac{f(x_n)}{f'(x_n)}$ to get the second and third approximations.

2 Use the substitution $1+\sin x = u$. Very straightforward.

3 Image too small to read fully, but it looks as though you need to expand $k(k-2)(k+2)$ to get $k^3-4k$, and then sum these two terms separately.

Grandad
• Dec 29th 2008, 09:53 AM
ea12345
plz step by step solution
• Dec 29th 2008, 01:11 PM
mr fantastic
Quote:

Originally Posted by ea12345
plz step by step solution

You've been given help to get started. Having carefuly read and thought about this help (I assume), you now need to be much more specific than the above statement.

Please explain what you've tried and where you get stuck.
• Apr 18th 2009, 04:52 PM
mr fantastic
Quote:

Originally Posted by ea12345
Q.1 Use Newton’s method to find the value of x for the function
f(x)=2x^2+4x-3=0 ; x>0

Note: Perform only 3 iterations.

Q2 and Q3 in attachment

thanks in advance

See here also: http://www.mathhelpforum.com/math-he...ns-method.html

Thread closed.