0

I'm going through an old test paper. Some more info was given: the answer lies in the interval $-20\le x\le 20$. There are several solutions, the question is to find the smallest and the total number of solutions. The first solution is $5.996$, but I can't for the life of me figure out how to get started on this problem.

Vladimir Vargas
  • 4,635
victoriah
  • 121
  • 2
    Use a rough plot by hand of $y=\cos 2x$ and $y=2-x/5$ to locate the appropriate solution approximately, then a numerical method. – André Nicolas Jan 21 '15 at 19:03

1 Answers1

1

How to get started.... I would undoubtedly sketch a graph first.

enter image description here

As you know, mathematicians work it out with a pencil.

Joffan
  • 39,627