How to handle 1/x + 1/(2x+1), x>0

in the solver it is not dcp

You will benefit from reading or re-reading the CVX Usersâ€™ Guide. Have you read http://cvxr.com/cvx/doc/funcref.html#new-functions ?

help inv_pos

inv_pos Reciprocal of a positive quantity.

inv_pos(X) returns 1./X if X is positive, and +Inf otherwise.

X must be real.`For matrices and N-D arrays, the function is applied to each element. Disciplined convex programming information: inv_pos is convex and nonincreasing; therefore, when used in CVX specifications, its argument must be concave (or affine).`

Excuse me, how to express 1/(x(x+1)) in CVX?