2) Prove that:sec 6A-tan A= 1 + 3sec 2Ax tan 2A​

It will be 70 meters Take away 20 from 150 continually. 150-20=130. 130-20=110 110-20=90 90-20=70 it took 4 minutes, as it takes 4 times to get to 70. Then add 15 to 10 continually. 10+15=25 25+15=40 40+15=55. 55+15=70. It shows clearly it takes 4 minutes again as it was calculated 4 times, therefor the answer is 70metres. Or 4 minutes in.