Erin is buying produce at a store. she buys c cucumbers at $0.99 each and a apples at $0.79 each. what does the expression 0.99c+0.79a represent

James adds two numbers a + b. sally adds the same two numbers but reverse the order b + a what property of addition assures us that james and sally will get the same sum

What is the range? can’t seem to find it out

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).