Question

Se senx = -3/5, com x € 4 quadrante então qual o valor da tgx?

Answer 1

4 Quadrante: sen = - ; cos = + ; tg = -

sen2x + cos2x = 1
9/25 + cos2x = 1
cos2x = 25/25 - 9/25
cos2x = 16/25
cosx = 4/5

tgx = senx/ cosx = -3/5/4/5 = - 3.5 / 5.4
tgx = -3/4