17.3 CHAPTER 17. TRIGONOMETRY
(a) sin163◦
(b) cos327◦
(c) tan248◦
(d) cos213◦- Determine the following without the use of acalculator:
(a) (tan 150◦)(sin 30◦) + cos 330◦
(b) (tan 300◦)(cos 120◦)
(c) (1− cos 30◦)(1− sin 210◦)
(d) cos 780◦+ (sin 315◦)(tan 420◦)- Determine the following by reducing to an acute angle and using special angles. Do not usea
calculator:
(a) cos 300◦
(b) sin 135◦
(c) cos 150◦
(d) tan 330◦
(e) sin 120◦
(f) tan^2225 ◦
(g) cos 315◦
(h) sin^2420 ◦
(i) tan 405◦
(j) cos 1020◦
(k) tan^2135 ◦
(l) 1 − sin^2210 ◦More practice video solutions or help at http://www.everythingmaths.co.za(1.) 014i (2.) 014j (3.) 014k (4.) 014mFunction Values of (−θ)
When the argument of atrigonometric function is (−θ) we can add 360 ◦without changing the result.
Thus for sine and cosine
sin(−θ) = sin(360◦− θ) =−sin θ
cos(−θ) = cos(360◦− θ) = cos θ
Function Values of 90 ◦± θ
Activity: Reduction Formulae forFunction Values of 90 ◦±θ
- Function values of (90◦− θ)