Y=12-2x in a chart to me do my homework because im stuck and i dont know what to do

Find the value of the cosine for angle a

The weight of a radioactive isotope was 96 grams at the start of an experiment. after one hour, the weight of the isotope was half of its initial weight. after two hours, the weight of the isotope was half of its weight the previous hour. if this pattern continues, which of the following graphs represents the weight of the radioactive isotope over time? a. graph w b. graph x c. graph y d. graph z

What is the effect on the graph of the function f(x) = x2 when f(x) is changed to f(x) − 4?