Trigonometry I

Abstract

After working through this chapter you should be able to

• (1) Determine the values of the trigonometric ratios for angles from 0° to 360° inclusive.

• (2) Derive the relationships tan θ = sin θ/cos θ and sin² θ + cos² θ = 1 for a right-angled triangle.

• (3) Plot the graphs of sin θ, cos θ and tan θ for angles from 0° to 360° inclusive.

• (4) State the sine and cosine rules.

• (5) State the conditions under which these rules may be used.

• (6) Use these rules to calculate unknown sides and angles in any triangle.

• (7) Solve practical problems using these rules.

• (8) Calculate the area of any triangle using the formulae ½ab sin C and √ [s (s − a) (s −b) (s − c)].