Solving inequalities

**kandyfloss** · November 28th, 2011, 05:42 AM

Solve ln(2x+1)>3cosx
how do i proceed?

**Plato** · November 28th, 2011, 06:09 AM

Originally Posted by kandyfloss

Solve ln(2x+1)>3cosx how do i proceed?

Graph $\ln(2x+1)-3\cos(x)$ .
That will be a start.

**princeps** · November 28th, 2011, 06:18 AM

Originally Posted by kandyfloss

Solve ln(2x+1)>3cosx
how do i proceed?

Plot of: $\ln(2x+1)-3\cos x$

**kandyfloss** · November 28th, 2011, 06:22 AM

thanks princeps, okay so from the graph above. i can say ln(2x+1)-3cosx is >0 for 1.2<x<5.8 and 6.7<x<10 right?

**princeps** · November 28th, 2011, 07:10 AM

Originally Posted by kandyfloss

thanks princeps, okay so from the graph above. i can say ln(2x+1)-3cosx is >0 for 1.2<x<5.8 and 6.7<x<10 right?

you may conclude that 1.2 < x < 5.8 and x > 6.7 approximately

Math Help Forum: Solving inequalities