Topic 4: Trigonometry (III)

Given that sin (x +200) = 0.7660, find x, to the nearest degree, for 00 ≤ x≤ 360.         (3 marks)

                                                                                                                               [KCSE 2013 PP1 No. 8]

Solve the equation 6cos2x + 7sin x - 8 = 0 for 00 ≤ x ≤ 90.0                                            (4 marks)

                                                                                                                             [KCSE 2013 PP1 No. 14] 

 Determine the amplitude and period of the function, Y = 2 cos (3x —45)0                              (2 marks)

                                                                                                                               [KCSE 2014 PP2 No. 6]

Find in radius, the value of x in the interval 00 ≤ x ≤ 2πc for which 2 cos2 x - sin x =1

                      (Leave your answer in terms of z).                                                            (4 marks)

                                                                                                                             [KCSE 2016 PP2 No. 16]

  Determine the amplitude and the phase angle of the curve:  

                    y = sin (4ϴ + 600).                                                                                       (3 marks)

                                                                                                                             [KCSE 2017 PP2 No. 12]  

State the amplitude and the phase angle of the curve y = 2sin (x – 300).                    (2 marks) 

                                                                                                                             [KCSE 2018 PP2 No. 10]

Determine the amplitude and the period of the function y = 3sin (2x + 400).                (2 marks)

                                                                                                                           [KCSE 2019 PP2 No. 10]

Solve the equation sin 2 ϴ - cos 2ϴ = for 0 0 ≤ ϴ ≤ 360.                                         (4 marks)

                                                                                                                             [KCSE 2020 PP2 No. 14]

The equation of a trigonometric wave is y= 4sin (ax - 70)0. The wave has a period of 1800 (a)  

(a) Determine the value of a.                                                                                                 (l mark)

(b) Deduce the phase angle of the wave.                                                                              (l mark)

                                                                                                                     [KCSE 2021 PP2 No. 10]