Question

In Problems 81–92, use a graphing utility to solve each equation. Express the solution(s) rounded to two decimal places.

$x+5\cos x=0$

Short answer

The solution set is$\left\{-1.31,1.98,3.84\right\}$.

Step-by-step solution

Step 1. Given Information

In the given problems we have to use a graphing utility to solve each equation and express the solution(s) rounded to two decimal places.

$x+5\cos x=0$

Step 2. This type of trigonometric equation cannot be solved by previous methods. A graphing utility, though, can be used here.

Each solution of this equation is the x-coordinate of a point of intersection of the graphs of.

Step 3. The graph of the given equation is

Step 4. There are three points of intersection; the x-coordinates are the solutions that we seek.

Using INTERSECT, we find

$x=-1.31x=1.98x=3.84$

The solution set is$\left\{-1.31,1.98,3.84\right\}$.