Elements of representation theory

6901. Prove that the mapping ρ: ℤ → GL₂(ℂ) for which ρ ( n ) = ( 1 n 0 1 ) ( n   ∈   ℤ ) , https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203756454/84bc859e-388a-4821-81f7-7fb447dc7024/content/eq2014.tif"/>