Solve this and show work​

Which of the following is the true for f(x) = 5cos

Find the domain and range of the following function f(x) = 51x - 21+ 4

Which equation could represent the relationship shown in the scatter plot? y=−3x−2 y=−3/4x+10 y=−2/3x+1 y=9x−12 scatter plot with x axis labeled variable x and y axis labeled variable y. points go from upper left to lower right.