Saturday

April 19, 2014

April 19, 2014

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

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

- trig -
**Steve**, Monday, October 3, 2011 at 5:32am2 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.

**Related Questions**

trig - how can i find all the exact solutions to the equation : 2cos^2x + 3sinx...

trig - Find the solutions to the equation cos2x=sinx and 2cos^2x-3cosx-3=0

trig - find the exact solutions 2cos^2x+3sinx=0 the way it stands, that is a "...

Pre-Calculus - Find all solutions to the equation in the interval [0, 2pi) cos4x...

Trig - 2cos^2Beta-Cosbeta=0 (find all solutions for the equation in the interval...

trig - Find ALL solutions to the equation on the interval [0, 2pie]: 2sin(1/2X...

Math - Solving for Trig Equations - Solve the following equation for 0 less than...

Trig - Find all solutions of the equation on the interval [0,2pi): Tan^2x=1-secx

Trig - Find all solutions of equation on interval [0,2pi] 1=cot^2x + cscx

trig - Find all solutions of the equation 2sin^2x-cosx=1 in the interval [0,2pi...