How can I find the points of intersection of cosh(x) and sec(x)?
Plotting the two, I can see that it has a root around 4.7, but then I can't tell where the next root is.
But when I use FindRoot
with a guess of 4.7 I don't get the root but if I use a guess between 4.72 and 4.8 then I find the root - 4.730040744862704.
Also, another root - 7.8532046241 can be found by guessing between 7.83 and 7.85.
Q: Is there a better way to solve the equation: Cosh[x]==Sec[x]
?
Q: How do I see the other points of intersection of the graphs y=Cosh[x]
and y=Sec[x]
?
Any help would be much appreciated. Thanks!
FindRoot
uses newtons method when you give it a single point and the secant method when you supply 2. The derivative of your function is very large near the root so newtons method shoots off far away from your guess on the first iteration. $\endgroup$