GCSE · Graphs of functions

Trigonometric graphsExam-style questions

The sine and cosine waves from 0° to 360° — where they start, peak and cross — why they never leave the band −1 to 1, and how wave symmetry finds the second solution of sin x = k.

11 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 3Level 4Level 5
  1. 1
    The diagram shows a sketch of the curve with equation y=tan⁡x°y = \tan x° for 0≤x≤3600 \le x \le 360, together with the lines with equations y=ky = k and y=−ky = -k, where kk is a positive constant.ABCD90180270360Oy = ky = −kxyThe line y=ky = k meets the curve at the points AA and BB.

    The line y=−ky = -k meets the curve at the points CC and DD.

    The xx-coordinate of AA is 6060
    (a) Find the exact value of kk.

    (1 mark)
    (b) Find the xx-coordinate of each of the points BB, CC and DD.

    (3 marks)
    Level 5 · 4 marksTry it
  2. 2
    The diagram shows the graph of y=sin⁡xy = \sin x for 0°≤x≤360°0° \le x \le 360°50100150200250300350-1.5-1-0.50.511.5x°yYou are given that sin⁡30°=0.5\sin 30° = 0.5

    (a) Find the other solution of sin⁡x=0.5\sin x = 0.5 for 0°≤x≤360°0° \le x \le 360°

    (b) Write down the smallest solution of sin⁡x=−0.5\sin x = -0.5 for 0°≤x≤360°0° \le x \le 360°
    Level 5 · 3 marksTry it
  3. 3
    The diagram shows the graph of y=cos⁡xy = \cos x for 0°≤x≤360°0° \le x \le 360°50100150200250300350-1.5-1-0.50.511.5x°yYou are given that cos⁡60°=0.5\cos 60° = 0.5

    Find the other solution of cos⁡x=0.5\cos x = 0.5 for 0°≤x≤360°0° \le x \le 360°
    Level 5 · 2 marksTry it
  4. 4
    The diagram shows the graph of y=cos⁡xy = \cos x for 0°≤x≤360°0° \le x \le 360°50100150200250300350-1.5-1-0.50.511.5x°ycos⁡40°=0.766\cos 40° = 0.766, correct to 3 decimal places.

    (a) Use the graph to write down another solution of cos⁡x=0.766\cos x = 0.766 for 0°≤x≤360°0° \le x \le 360°

    (b) Use the graph to solve cos⁡x=−0.766\cos x = -0.766 for 0°≤x≤360°0° \le x \le 360°
    Level 5 · 3 marksTry it
  5. 5
    The diagram shows the graph of y=2sin⁡xy = 2\sin x for 0°≤x≤360°0° \le x \le 360°50100150200250300350-2-112x°y(a) Write down the maximum and minimum values of y=2sin⁡xy = 2\sin x

    (b) Solve 2sin⁡x=12\sin x = 1 for 0°≤x≤360°0° \le x \le 360°
    Level 5 · 4 marksTry it