Given:
The trigonometric ratios are given as,
The objective is to find out which of these expressions is positive or negative.
Step-by-step explanation:
Consider the first expression and convert it as,
Using the trigonometric identities,
The equation (1) can be written as,
Thus, tan(143°) is a negative expression.
Consider the second trigonometric expression.
Thus, cos (π/3) is a positive expression.
Consider the third trigonometric expression.
Thus, sin 362° is a positive expression.
Consider the fourth expression.