Question

sendo dado 5 tg²x+12sec²x=29, calcule cosx

Answer 1

5tg²x + 12sec²x = 29

5sen²x / cos²x + 12 / cos²x = 29

(5sen²x + 12) / cos²x = 29

5sen²x + 12 = 29cos²x

5(1 - cos²x) + 12 = 29cos²x

5 - 5cos²x + 12 = 29cos²x

17 = 34cos²x

cos²x = 1/2

cosx = 1/√2

cosx = √2/2

x = 45°