PutnamSuperchallengeIntegrals I: Feynman's Trick ShareIntegrals I: Feynman's Trick · Superchallenge problemHow many invertible 2×22\times22×2 matrices are there over the field F7\mathbb{F}_{7}F7 (that is, ∣GL2(F7)∣|GL_2(\mathbb{F}_{7})|∣GL2(F7)∣)?Check Show answer Walk through it step by step Practice more like this Review this concept