Posted by **sam** on Sunday, October 2, 2011 at 5:12pm.

Find all solutions to the equation

2cos(2x) = x + 1, correct to 4 decimal places.

- trig -
**Steve**, Monday, October 3, 2011 at 5:32am
2 cos(2x) never gets out of the range [-2,2]

So, whenever |x+1| > 2, there are no solutions.

That means all solutions are in [-3,1]

A little Newton-Raphson should work nicely here, or a bisection method.

## Answer This Question

## Related Questions

- trig - how can i find all the exact solutions to the equation : 2cos^2x + 3sinx...
- Calculus - Find all solutions of the equation correct to three decimal places. (...
- trig - Find the solutions to the equation cos2x=sinx and 2cos^2x-3cosx-3=0
- Trig - 2cos^2Beta-Cosbeta=0 (find all solutions for the equation in the interval...
- trigonometry - Find all solutions on the interval [0.2pi) A) -3sin(t)=15cos(t)...
- Precalculus II - Find all real solutions to four decimal places to the equation ...
- trig - I need to find all solutions of the given equations for the indicated ...
- Trigonometry - Find all solutions between 0 and 2pi. Round to two decimal places...
- Trig - Finding all Solutions for 2cos(x)-3=0
- Math: Calculus - Can someone help me out here with these two problem? I have ...

More Related Questions