Need help asap. circle geometry

Prove sin2a + cos2a - 1 / sin2a + cos2a + 1 = 1 - tana / 1 + cota

Question 9 of 10 2 points suppose your sat score is 1770. you look up the average sat scores for students admitted to your preferred colleges and find the list of scores below. based on your sat score of 1770, which average score below represents the college that would be your best option? o a. 1790 o b. 2130 o c. 2210 od. 1350

Two years ago a man was six times as old as his daughter. in 18 years he will be twice as old as his daughter. determine their present ages.