Mathematics 10 — Exercise 7.1 · Q1 (ii)

Full question

Determine the algebraic sign (positive or negative) of cos 145°.

cos(145°)

Step-by-step solution

  1. 145° lies in quadrant 2.

  2. In quadrant I all six ratios are positive. In quadrant II only sine and cosecant are positive.

Answer

Negative (−).