roots of non linear periodic function

Hi, i need to find roots of following equation (x). L and P are constants. using fzero i cant, please guid

(x*L)*tan(x*L)=P

i am attempting as follow but fails:

function  C(x)
x*L*tan(x*L))=P

Answer 1

[Walter Roberson]

format long g

rng(655321)
L = randn()

L = 
        -0.486212438021384

P = rand() * 10

P = 
          3.86360763118074

C = @(x) x.*L.*tan(x*L)-P

C = function_handle with value:
    @(x)x.*L.*tan(x*L)-P

root1 = fzero(C, pi/3)

root1 = 
          2.58404586473783

N = 10;
nroots = zeros(1,N);
proots = zeros(1,N);
for K = 1 : N
    nroots(K) = fzero(C, root1-K*pi);
    proots(K) = fzero(C, root1+K*pi);
end
uniquetol([nroots, root1, proots].')

ans = 19×1

-29.0761112543409 -26.445774714587 -22.6147531978207 -20.1564225125044 -16.1533951413005 -13.9854187445272 -9.6920370847803 -8.06185601128258 -3.2306790282601 2.58404586473783

Answer 2

[KSSV]

syms x  
p = pi/4 ; 
L = 2 ; 
eqn = x*L*tan(x*L)-p==0 ;
s = vpasolve(eqn,x)