What is the y-intercept for this problem. i already tried 10 n it was wrong

1. preform the indicated operation. then estimate to see whether the proposed result is reasonable. 811.1 - 8.039 803.071 803.061 803.161 831.061 2. the ordered pair (1, 2) lies in which quadrant? quadrant ii quadrant iv quadrant iii quadrant i 3. sean tries to drink 3 liters of water every day how my millimeters of water does he drink in a day? 0.3 ml 0.003 ml 3,000 ml 30 ml 4. find the least common multiple. (lcm). 10, 36 5 180 20 360

The square pyramid has a volume of 441 cubic inches. what is the value of x? 1/7x is the height x is the base

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.