Multiple independent equations

Solve two or more completely separate trigonometric equations (e.g., part (i) and part (ii) with unrelated equations), each requiring independent solution methods.

38 questions · Moderate -0.2

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CAIE P1 2024 November Q8
8 marks Moderate -0.3
8
  1. It is given that \(\beta\) is an angle between \(90 ^ { \circ }\) and \(180 ^ { \circ }\) such that \(\sin \beta = a\).
    Express \(\tan ^ { 2 } \beta - 3 \sin \beta \cos \beta\) in terms of \(a\). \includegraphics[max width=\textwidth, alt={}, center]{e32902b8-a259-4572-982e-2a35413b81b2-11_2726_35_97_20}
  2. Solve the equation \(\sin ^ { 2 } \theta + 2 \cos ^ { 2 } \theta = 4 \sin \theta + 3\) for \(0 ^ { \circ } < \theta < 360 ^ { \circ }\).
CAIE P1 2015 June Q4
6 marks Moderate -0.8
4
  1. Express the equation \(3 \sin \theta = \cos \theta\) in the form \(\tan \theta = k\) and solve the equation for \(0 ^ { \circ } < \theta < 180 ^ { \circ }\).
  2. Solve the equation \(3 \sin ^ { 2 } 2 x = \cos ^ { 2 } 2 x\) for \(0 ^ { \circ } < x < 180 ^ { \circ }\).
Edexcel C12 2015 January Q14
10 marks Standard +0.3
14. In this question, solutions based entirely on graphical or numerical methods are not acceptable.
  1. Solve, for \(0 \leqslant x < 360 ^ { \circ }\), $$3 \sin x + 7 \cos x = 0$$ Give each solution, in degrees, to one decimal place.
  2. Solve, for \(0 \leqslant \theta < 2 \pi\), $$10 \cos ^ { 2 } \theta + \cos \theta = 11 \sin ^ { 2 } \theta - 9$$ Give each solution, in radians, to 3 significant figures.
Edexcel C12 2017 January Q11
10 marks Moderate -0.3
11. In this question solutions based entirely on graphical or numerical methods are not acceptable.
  1. Solve, for \(0 \leqslant x < 2 \pi\), $$3 \cos ^ { 2 } x + 1 = 4 \sin ^ { 2 } x$$ giving your answers in radians to 2 decimal places.
  2. Solve, for \(0 \leqslant \theta < 360 ^ { \circ }\), $$5 \sin \left( \theta + 10 ^ { \circ } \right) = \cos \left( \theta + 10 ^ { \circ } \right)$$ giving your answers in degrees to one decimal place.
Edexcel C12 2018 January Q5
11 marks Standard +0.3
5. (In this question, solutions based entirely on graphical or numerical methods are not acceptable.)
  1. Solve, for \(0 < \theta < \frac { \pi } { 2 }\) $$5 \sin 3 \theta - 7 \cos 3 \theta = 0$$ Give each solution, in radians, to 3 significant figures.
  2. Solve, for \(0 < x < 360 ^ { \circ }\) $$9 \cos ^ { 2 } x + 5 \cos x = 3 \sin ^ { 2 } x$$ Give each solution, in degrees, to one decimal place.
Edexcel C12 2018 June Q12
10 marks Standard +0.3
12. [In this question solutions based entirely on graphical or numerical methods are not acceptable.]
  1. Solve for \(0 \leqslant x < 360 ^ { \circ }\), $$5 \sin \left( x + 65 ^ { \circ } \right) + 2 = 0$$ giving your answers in degrees to one decimal place.
  2. Find, for \(0 \leqslant \theta < 2 \pi\), all the solutions of $$12 \sin ^ { 2 } \theta + \cos \theta = 6$$ giving your answers in radians to 3 significant figures.
Edexcel C12 Specimen Q14
10 marks Moderate -0.3
  1. In this question you must show all stages of your working. (Solutions based entirely on graphical or numerical methods are not acceptable.)
    1. Solve for \(0 \leqslant x < 360 ^ { \circ }\), giving your answers in degrees to 1 decimal place,
    $$3 \sin \left( x + 45 ^ { \circ } \right) = 2$$
  2. Find, for \(0 \leqslant x < 2 \pi\), all the solutions of $$2 \sin ^ { 2 } x + 2 = 7 \cos x$$ giving your answers in radians. \includegraphics[max width=\textwidth, alt={}, center]{1528bec3-7a7a-42c5-bac2-756ff3493818-35_108_95_2572_1804}
Edexcel P2 2022 January Q7
8 marks Standard +0.3
7. In this question you must show all stages of your working. Solutions relying entirely on calculator technology are not acceptable.
  1. Solve, for \(- 90 ^ { \circ } < x < 90 ^ { \circ }\), the equation $$3 \sin \left( 2 x - 15 ^ { \circ } \right) = \cos \left( 2 x - 15 ^ { \circ } \right)$$ giving your answers to one decimal place.
  2. Solve, for \(0 < \theta < 2 \pi\), the equation $$4 \sin ^ { 2 } \theta + 8 \cos \theta = 3$$ giving your answers to 3 significant figures.
Edexcel P2 2023 January Q8
9 marks Standard +0.3
  1. In this question you must show all stages of your working.
Solutions based entirely on calculator technology are not acceptable.
  1. Solve, for \(- \frac { \pi } { 2 } < x < \pi\), the equation $$5 \sin ( 3 x + 0.1 ) + 2 = 0$$ giving your answers, in radians, to 2 decimal places.
  2. Solve, for \(0 < \theta < 360 ^ { \circ }\), the equation $$2 \tan \theta \sin \theta = 5 + \cos \theta$$ giving your answers, in degrees, to one decimal place.
Edexcel P2 2021 October Q10
10 marks Standard +0.3
10. In this question you must show all stages of your working. Solutions relying entirely on calculator technology are not acceptable.
  1. Solve, for \(- \frac { \pi } { 2 } < x < \frac { \pi } { 2 }\) $$\tan ^ { 2 } \left( 2 x + \frac { \pi } { 4 } \right) = 3$$
  2. Solve, for \(0 < \theta < 360 ^ { \circ }\) $$( 2 \sin \theta - \cos \theta ) ^ { 2 } = 1$$ giving your answers, as appropriate, to one decimal place.
Edexcel C2 2006 January Q8
9 marks Moderate -0.8
  1. (a) Find all the values of \(\theta\), to 1 decimal place, in the interval \(0 ^ { \circ } \leqslant \theta < 360 ^ { \circ }\) for which
$$5 \sin \left( \theta + 30 ^ { \circ } \right) = 3$$ (b) Find all the values of \(\theta\), to 1 decimal place, in the interval \(0 ^ { \circ } \leqslant \theta < 360 ^ { \circ }\) for which $$\tan ^ { 2 } \theta = 4$$
Edexcel C2 2005 June Q5
8 marks Moderate -0.8
5. Solve, for \(0 \leqslant x \leqslant 180 ^ { \circ }\), the equation
  1. \(\quad \sin \left( x + 10 ^ { \circ } \right) = \frac { \sqrt { } 3 } { 2 }\),
  2. \(\cos 2 x = - 0.9\), giving your answers to 1 decimal place.
Edexcel C2 2008 June Q9
10 marks Moderate -0.8
9. Solve, for \(0 \leqslant x < 360 ^ { \circ }\),
  1. \(\quad \sin \left( x - 20 ^ { \circ } \right) = \frac { 1 } { \sqrt { 2 } }\)
  2. \(\cos 3 x = - \frac { 1 } { 2 }\)
Edexcel C2 2009 June Q7
10 marks Moderate -0.3
7. (i) Solve, for \(- 180 ^ { \circ } \leqslant \theta < 180 ^ { \circ }\), $$( 1 + \tan \theta ) ( 5 \sin \theta - 2 ) = 0$$ (ii) Solve, for \(0 \leqslant x < 360 ^ { \circ }\), $$4 \sin x = 3 \tan x .$$
Edexcel C2 2011 June Q7
10 marks Moderate -0.3
  1. (a) Solve for \(0 \leqslant x < 360 ^ { \circ }\), giving your answers in degrees to 1 decimal place,
$$3 \sin \left( x + 45 ^ { \circ } \right) = 2$$ (b) Find, for \(0 \leqslant x < 2 \pi\), all the solutions of $$2 \sin ^ { 2 } x + 2 = 7 \cos x$$ giving your answers in radians.
You must show clearly how you obtained your answers.
Edexcel C2 2013 June Q9
12 marks Standard +0.3
  1. (i) Solve, for \(0 \leqslant \theta < 180 ^ { \circ }\)
$$\sin \left( 2 \theta - 30 ^ { \circ } \right) + 1 = 0.4$$ giving your answers to 1 decimal place.
(ii) Find all the values of \(x\), in the interval \(0 \leqslant x < 360 ^ { \circ }\), for which $$9 \cos ^ { 2 } x - 11 \cos x + 3 \sin ^ { 2 } x = 0$$ giving your answers to 1 decimal place. You must show clearly how you obtained your answers.
Edexcel C2 2014 June Q7
8 marks Standard +0.3
7. (i) Solve, for \(0 \leqslant \theta < 180 ^ { \circ }\), the equation $$\frac { \sin 2 \theta } { ( 4 \sin 2 \theta - 1 ) } = 1$$ giving your answers to 1 decimal place.
(ii) Solve, for \(0 \leqslant x < 2 \pi\), the equation $$5 \sin ^ { 2 } x - 2 \cos x - 5 = 0$$ giving your answers to 2 decimal places. (Solutions based entirely on graphical or numerical methods are not acceptable.)
Edexcel C2 2014 June Q7
9 marks Moderate -0.3
7. (i) Solve, for \(0 \leqslant \theta < 360 ^ { \circ }\), the equation $$9 \sin \left( \theta + 60 ^ { \circ } \right) = 4$$ giving your answers to 1 decimal place.
You must show each step of your working.
(ii) Solve, for \(- \pi \leqslant x < \pi\), the equation $$2 \tan x - 3 \sin x = 0$$ giving your answers to 2 decimal places where appropriate. [Solutions based entirely on graphical or numerical methods are not acceptable.]
Edexcel C2 2015 June Q8
9 marks Moderate -0.3
8. (i) Solve, for \(0 \leqslant \theta < \pi\), the equation $$\sin 3 \theta - \sqrt { 3 } \cos 3 \theta = 0$$ giving your answers in terms of \(\pi\).
(ii) Given that $$4 \sin ^ { 2 } x + \cos x = 4 - k , \quad 0 \leqslant k \leqslant 3$$
  1. find \(\cos x\) in terms of \(k\).
  2. When \(k = 3\), find the values of \(x\) in the range \(0 \leqslant x < 360 ^ { \circ }\)
Edexcel C2 2016 June Q6
9 marks Moderate -0.3
6. (i) Solve, for \(- \pi < \theta \leqslant \pi\), $$1 - 2 \cos \left( \theta - \frac { \pi } { 5 } \right) = 0$$ giving your answers in terms of \(\pi\).
(ii) Solve, for \(0 \leqslant x < 360 ^ { \circ }\), $$4 \cos ^ { 2 } x + 7 \sin x - 2 = 0$$ giving your answers to one decimal place.
(Solutions based entirely on graphical or numerical methods are not acceptable.)
Edexcel C2 2018 June Q8
9 marks Moderate -0.3
8 In this question solutions based entirely on graphical or numerical methods are not acceptable.
  1. Solve for \(0 \leqslant x < 360 ^ { \circ }\), $$4 \cos \left( x + 70 ^ { \circ } \right) = 3$$ giving your answers in degrees to one decimal place.
  2. Find, for \(0 \leqslant \theta < 2 \pi\), all the solutions of $$6 \cos ^ { 2 } \theta - 5 = 6 \sin ^ { 2 } \theta + \sin \theta$$ giving your answers in radians to 3 significant figures.
Edexcel C2 Q8
10 marks Moderate -0.3
  1. (a) Solve, for \(0 \leq x < 360 ^ { \circ }\), the equation \(\cos \left( x - 20 ^ { \circ } \right) = - 0.437\), giving your answers to the nearest degree.
    (b) Find the exact values of \(\theta\) in the interval \(0 \leq \theta < 360 ^ { \circ }\) for which
$$3 \tan \theta = 2 \cos \theta$$
\includegraphics[max width=\textwidth, alt={}]{9e4e1626-238b-4afd-b81c-68c5ab1624c2-13_2536_1737_150_98}
OCR C2 2006 June Q5
8 marks Moderate -0.3
5 Solve each of the following equations, for \(0 ^ { \circ } \leqslant x \leqslant 180 ^ { \circ }\).
  1. \(2 \sin ^ { 2 } x = 1 + \cos x\).
  2. \(\sin 2 x = - \cos 2 x\).
OCR C2 Q5
8 marks Moderate -0.3
5. (i) Given that \(\sin \theta = 2 - \sqrt { 2 }\), find the value of \(\cos ^ { 2 } \theta\) in the form \(a + b \sqrt { 2 }\) where \(a\) and \(b\) are integers.
(ii) Find, in terms of \(\pi\), all values of \(x\) in the interval \(0 \leq x < \pi\) for which $$\cos 3 x = \frac { \sqrt { 3 } } { 2 }$$
OCR C2 Q8
11 marks Standard +0.3
8. (i) Find, to 2 decimal places, the values of \(x\) in the interval \(0 \leq x < \pi\) for which $$\tan 2 x = 3$$ (ii) Find, in terms of \(\pi\), the values of \(y\) in the interval \(0 \leq y < 2 \pi\) for which $$2 \sin y = \tan y$$