MATLAB: Finding epsilon satisfy a trigonometric function.

functionmatlab functionvariable

I need to find the value of epsilon (e) that satisfy the function cot(e)^2*cot(2*e)^2 == sin(2*e)^2 where pi/4<e<pi/2

Thanks a lot. I found the solution. I share it here if someone want to use it.

syms x
f = cot(x).^2*cot(2*x).^2 - sin(2*x).^2;
 vpasolve(f,[pi/3 pi/2])
ans =
1.326722925756775867399902790294

Use ./ instead of /

x = -2*pi:.1:2*pi;
y = 2e-6*sin(x).*cos(x)./(10.5e-12*sin(x).^2+13.8e-12*cos(x).^2);
plot(x,y)

x = linspace(-2*pi,2*pi,1000);
y = (mod(x+pi,2*pi)-pi).^3;
plot(x,y)