1. Write the resulting set of these Cartesian products (a) fa, b,c} x 1,2 (b) red, black', 'green' x f'sauce', 'grass'^ 2. What are the domain, codomain, and image of the following functions: (a) g:Z-Z+ with f(n) n5 (b) f:R-R with f(n) -2n/(n+1) (c) go f (d) f-1 3. Prove whether the following functions are injective, surjective, or bijective: (a) f R-1with f(n)- 2n/(n1) (b) g:Z-+Z with f(n) In5 (c) gof (d) f-1