solving problem exp(x) - 2cos(x) = 0

Posted on 2008-03-14 07:00 By Kagez (2)

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How do I ...? with Maple (Student)

hi everone,

i m new user . My dad just got for me MAPLE 11 last week. So interested! But when i do sloving equtaion 2*cos(x) - exp(x)= 0 interval -3..3. Maple only give me 1 solution instead of 2 solutions . I wonder if i my imput date is wrong. Can anyone help me, thx!

fsolve([exp(x) - 2*cos(x) = 0],x=-3..3);
{x = .5397851608}

2 options

Comment on 2008-03-14 10:14 from Scott03 ( Maple Rating 4

468)

One option to get both the solutions is with the avoid option for fsolve. It would look something like this

fsolve([exp(x) - 2*cos(x) = 0],x=-3..3);

fsolve([exp(x) - 2*cos(x) = 0],x=-3..3,avoid=%);

This tells fsolve to avoid the solution that was given in the previous output (which should be the line above if it was executed first).

Another options is to use the Roots command found in the Student:-Calculus1 package. The following will give both those solutions you were looking for in one output

Student:-Calculus1:-Roots(exp(x)-2*cos(x), x = -3 .. 3, 'numeric');

Scott