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Mathematics LibreTexts

5.7E: More on Simpliying and Solving Equations with Trigonometric Functions (Exercises)

  • Page ID
    99756
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    Section 5.7 Exercises

    Part 2: Negative Angles

    21. If \(\tan(t)=-1.5\), find \(\tan(-t)\).

    22. If \(\cos(t)=0.23\), find \(\cos(-t)\).

    23. If \(\sin(t)=0.23\), find \(\sin(-t)\).

    Simplify each of the following expressions completely.

    27. \(\cot \left(-x\right)\cos \left(-x\right)+\sin \left(-x\right)\)

    28. \(\cos \left(-x\right)+\tan \left(-x\right)\sin \left(-x\right)\)

    Part 2: Angle sum identities

    Simplify each of the following to an expression involving a single trig function with no fractions.

    1. \(\sin(180^{circ}+\theta \)

    2. \(\cos(\pi-\theta \)

    30. \(\dfrac{1 + \text{tan}^2(b)}{\text{tan}^2(b)} = \text{csc}^2(b)\)

    31. \(\dfrac{\text{csc}^2 (x) - \text{sin}^2 (x)}{\text{csc} (x) + \text{sin} (x)} = \text{cos} (x) \text{cot} (x)\)

    33. \(\dfrac{\text{csc}^2 (\alpha) - 1}{\text{csc}^2 (\alpha) - \text{csc} (\alpha)} = 1 + \text{sin} (\alpha)\)

    36. \(2 \text{sec}^2 (t) = \dfrac{1 - \text{sin}(t)}{\text{cos}^2 (t)} + \dfrac{1}{1 - \text{sin} (t)}\)

    37. \(\dfrac{\text{sin}^4 (\gamma) - \text{cos}^4 (\gamma)}{\text{sin} (\gamma) - \text{cos} (\gamma)} = \text{sin} (\gamma) + \text{cos} (\gamma)\)

    23. \(\dfrac{1+\cot \left(t\right)}{1+\tan \left(t\right)}\)

    38. \(\dfrac{(1 + \text{cos}(A))(1 - \text{cos} (A))}{\text{sin} (A)} = \text{sin} (A)\)

    Solve the equation

    16. \( \sin(\theta+180^{circ})-sin(\theta)=1 \)

    Answer

    1. \(\dfrac{\pi}{4}\)

    3. \(-\dfrac{\pi}{6}\)

    5. \(\dfrac{\pi}{3}\)

    7. \(\dfrac{3\pi}{4}\)

    9. \(\dfrac{\pi}{4}\)

    11. \(-\dfrac{\pi}{3}\)

    13. 1.9823

    15. -0.9273

    17. \(44.427^{\circ}\)

    19. \(\dfrac{\pi}{4}\)

    21. \(-\dfrac{\pi}{6}\)

    23. \(\dfrac{2\sqrt{10}}{7}\)

    25. \(\dfrac{1}{\sqrt{17}}\)

    27. \(\dfrac{\sqrt{25-x^2}}{5}\)

    29. \(\dfrac{3x}{\sqrt{9x^2 + 1}}\)