Matrix Size Error using LQR

Hello,

I'm trying to calculate the observer ( L ) matrix of the following state-space system using the LQR command. When I run the code, I get the error "Error using lqr (line #) the R matrix must be square of size 1". I understand the error, but in my code I have an R matrix that IS size 1, so i'm unsure where the error is coming from. Ideally, once I find the L matrix I can calculate the transfer function of the system and make a bode plot.

Here is my code

A = [0 1; 0 0];
B = [0 ; 42.8625];
C = [1 0];
D = [0];
K = [1.8 0.25];
Q = [100 0; 0 10];
R = [1];
L = lqr(A',C',inv(R),inv(Q))'

%Error using lqr (line #)
%The R matrix must be square of size 1.

Thanks

[Jack Murphy]

Ah, I have my Q and R matrices confused while using the LQR command, so Q needs to be a square matrix of size 1.