One of your metamagic feats is easier to use.

Prerequisites: Any one metamagic feat, Knowledge Arcane/Nature/Religion score 15

Benefit: Choose a metamagic feat you already have you can reduce the cost of that one metamagic feat up to 3 times per day. When preparing or casting a spell modified by that feat, lower the spell-slot cost by one. You can never reduce the spell-slot cost below the spell's actual level.

Special: You may learn this feat multiple times each time for another metamagic feat. Its effects stack.