Question

Sendo x um ângulo do primeiro quadrante e tg x = 5, calcule sen x.

Answer 1

tgx = 5

cotgx = 1/5

cotg²x = 1/25

1 +cotg²x = 1 +1/25

cossec²x = 26/25

sen²x = 25/26

senx = √25/26 = 5/√26 = 5√26 /26 ✓