m = length(y)
h = sigmoid(X*theta);
J = (1/m)*(-y'*log(h) - (1 - y)'*log(1-h));

J = (1/m)*(-y'*log(h) - (1-y)'*log(1-h)) + (lambda/2*m)*sum(theta(2,:).^2)
 % theta(2:) implies i am adding from 2nd element and not the first one

grad = zeros(size(theta));
grad = (1/m)*X'*(h - y);

grad = (1/m)*X'*(h - y) + (lambda/m)*theta(2,:);