Ola joyce

cos(x) = 1/5

cos²(x) + sen²(x) = 1

1/25 + sen²(x) = 25/25

sen²(x) = 24/25

sen(x) = √24/5

sen(2x) = 2*sen(x)*cos(x) = 2*√24/5*1/5 = 2√24/25

cos(2x) = cos²(x) - sen²(x) = 1/25 - 24/25 = -23/25

tg(2x) = -2√24/23

cotg(2x) = -23/2√24 = -23√24/48

sec(2x) = -25/23

cossec(2x) = 25/2√24 = 25√24/48

pronto

muito obrigada ,me ajudou ,