Your picture is a bit blurry. What is the equation on WX and on ZY?
Cos -2x or -cos2x, it's the difference.
there seem to be pictures missing. can you reload the page without losing progress?
Answer:
9 + 2j is the required algebraic equation.
$7200.. you would find out what 3.5% of $6000 (210) is and then multiply it by 6 (1200) and then add it to the original $6000
