Functions (evaluate a funtion given its graph and drawing functions)

WARM UP

Please check if the next examples are functions or not and explain why:




How to evaluate a function given its graph:
https://www.khanacademy.org/math/algebra/algebra-functions/evaluating-functions/v/understanding-function-notation-example-2

More useful resources at:
http://mathequalslove.blogspot.com/2013/12/algebra-1-introduction-to-relations-and.html