<span>sin can be positive in 1st and 2nd quadrants.
cos can be negative in 2nd and 3rd quadrants.</span>
When comparing decimals, start in the tenths place. The decimal with the biggest value there is greater. If they are the same, move to the hundredths place and compare these values. If the values are still the same keep moving to the right until you find one that is greater or until you find that they are equal.
What are the coordinates of the 2 points?
Work out 9% of $87.00 then add theat to the $87.00 that will be the total cost. find how much cash she gave the cashier and then minus the total cost from that to find the change she got.