This will call the LaTeX interpreter correctly:
A= cos(tau)
l1 = sin(tau)
l2 = sin(tau + pi/8)
plot(tau, A, 'DisplayName', '$A(\tau)$'), hold on
plot(tau, l1, 'HandleVisibility','off'), hold on
plot(tau, l2, 'DisplayName', 'l with $\eta_0 = \pi - \asin(\sqrt{K})$')
hl = legend('show');
set(hl, 'Interpreter','latex')
You have an LaTeX syntax error in the third plot call (for ‘l2’). I will defer to you to solve that.
