Saturday

August 30, 2014

August 30, 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 - 2cos^2Beta-Cosbeta=0 (find all solutions for the equation in the interval...

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...

Math: Calculus - Can someone help me out here with these two problem? I have ...

maths - does this quadratic equation: 3x^2 - 2x - 9 = 0 have two solutions?? or ...

Trig - Finding all Solutions for 2cos(x)-3=0

math - Find all roots of the equation ln(4-x^2)=x correct to 8 decimal places. ...