Answer to Question #170978 in Trigonometry for Leighton

Question

Determine the values of x between 0o and 360o for EACH of the following

expressions:

(i) 2 sinx = 1

(ii) tanx = - 0.75 (iii) cosx = sin 5

Answer 1

(i) 2 sinx = 1

i.e., sinx = 1/2

x = arcsin(1/2)

$\therefore$ x = 30° or 150°

(ii) tanx = -0.75

x = arctan(-0.75)

$\therefore$ x = 323.13° or 143.13°

(iii) cosx = sin 5°

cosx = 0.087

x = arccos(0.087)

$\therefore$ x = 85° or 275°