Which relations are functions and which are not functions?
column a column b
1.
{(2, 2), (4, 4), (6, 6),
(8, 8)}
2.
{(0, 3), (3, 5), (5, 6),
(8, 4)}
3.
{(1, 2), (3, 3), (4, 8),
(6, 3)}
4.
{(3, 4), (5, 2), (5, 6),
(7, 3)}

a.
function
b.
not a function

Farmers know that driving heavy equipment on wet soil compresses the soil and injures future crops. here are data on the "penetrability" of the same type of soil at two levels of compression. penetrability is a measure of how much resistance plant roots will meet when they try to grow through the soil. compressed soil 2.85 2.66 3 2.82 2.76 2.81 2.78 3.08 2.94 2.86 3.08 2.82 2.78 2.98 3.00 2.78 2.96 2.90 3.18 3.16 intermediate soil 3.17 3.37 3.1 3.40 3.38 3.14 3.18 3.26 2.96 3.02 3.54 3.36 3.18 3.12 3.86 2.92 3.46 3.44 3.62 4.26 use the data, omitting the high outlier, to give a 95% confidence interval for the decrease in penetrability of compressed soil relative to intermediate soil. compute degrees of freedom using the conservative method. interval: to

The graph of a quadratic function has a maximum at point (0, 5). the graph contains the point (2, 1). what is another point on the graph?

What is the greatest common factor gcf of 10 and four