Question

найдите значение выражения 13(sin^2 53-cos^2 53)/cos 106

Answer 1

13*(-cos106)/cos106=-13

Answer 2

13(sin^2 53-cos^2 53)/cos106=13(1-cos^2 53- cos^2 53)/cos106=13(1-2cos^2 53)/cos106= -13(2cos^2 53-1)/cos106= -13cos2*53/cos106= -13cos106/cos106= -13