Question

Use the given point on the terminal side of angle θ to find the value of the trigonometric function indicated.

Answer 1

Answer:  19)  117°                    20) 53°

               21)  229°                   22) 119°

               23) 155°                    24) 323°

Step-by-step explanation:

Use Pythagorean Theorem to find r:     x² + y² = r²

19) x = $-\sqrt{17}$ ,  y = 8,    r = 9

     $\cos \theta=\dfrac{x}{r} \rightarrow \quad \cos \theta =\dfrac{-\sqrt{17}}{9} \rightarrow \quad \theta = cos^{-1}\bigg(\dfrac{-\sqrt{17}}{9}\bigg)\rightarrow \quad \theta = \large\boxed{117^o}$

20) x = 3,   y = 4,   r = 5

      $\cos \theta=\dfrac{x}{r} \rightarrow \quad \cos \theta =\dfrac{3}{5} \rightarrow \quad \theta = cos^{-1}\bigg(\dfrac{3}{5}\bigg)\rightarrow \quad \theta = \large\boxed{53^o}$

21) x = $-\sqrt7$,   y = -3,   r = 4

    $\sin \theta=\dfrac{y}{r} \rightarrow \quad \sin \theta =\dfrac{-3}{4} \rightarrow \quad \theta = sin^{-1}\bigg(\dfrac{-3}{4}\bigg)\rightarrow \quad \theta = \large\boxed{229^o}$    

22) x = $-\sqrt{15}$,   y = 7,   r = 8

     $\tan \theta=\dfrac{y}{x} \rightarrow \quad \tan \theta =\dfrac{7}{-\sqrt{15}} \rightarrow \quad \theta = tan^{-1}\bigg(\dfrac{7}{-\sqrt{15}}\bigg)\rightarrow \quad \theta = \large\boxed{119^o}$

23) x = -13,   y = 6,   r = $\sqrt{205}$

     $\tan \theta=\dfrac{y}{x} \rightarrow \quad \tan \theta =\dfrac{6}{-13} \rightarrow \quad \theta = tan^{-1}\bigg(\dfrac{6}{-13}\bigg)\rightarrow \quad \theta = \large\boxed{155^o}$

24) x = 4,    y = -3,   r = 5

     $\sin \theta=\dfrac{y}{r} \rightarrow \quad \sin \theta =\dfrac{-3}{5} \rightarrow \quad \theta = sin^{-1}\bigg(\dfrac{-3}{5}\bigg)\rightarrow \quad \theta = \large\boxed{323^o}$