hello everyone!I met a problem about how to express sqrt(2x+1)/(x+1) by CVX? I demonstrate mathematically that when x>0, sqrt(2x+1)/(x+1) is convex, but CVX rejects it. How on should I express it?thank you for your answer,please help me

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According to my calculations,

0 <= x <= sqrt(1/3). the expression is concave.

x >= sqrt(1/3), the expression is convex.

Hence is is not convex as you claim (nor is it concave).

Even if you further constrained the problem to x >= sqrt(1/3), it is doubtful this could be expressed in CVX due to not being convex over the entirety of its â€śnaturalâ€ť domain.

On the other hand, whether this can be used in CVX depends on whether the context allows some reformulation. For instance, the constraint `sqrt(2*x+1)/(x+1) >= 1`

could be rewritten as `sqrt(2*x+1) >= x+1`

, and entered directly as such in CVX.

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Understood Mark. Thanks, this helps me a lot.