Answer:
C
Step-by-step explanation:
[tex]\csc \theta= 1\dfrac{1}{4} \\\\\\\dfrac{1}{\sin\theta}=\dfrac{5}{4}[/tex]
Take the reciprocal of both sides:
[tex]\sin \theta =\dfrac{4}{5}[/tex]
You can now imagine a right triangle where the length of the side opposite this angle has a length of 4 and the hypotenuse has a length of 5. The third side by the Pythagorean theorem must therefore have a length of 3. The cosine of an angle is the length of the adjacent side divided by the length of the hypotenuse, or in this case:
[tex]\pm \dfrac{3}{5}[/tex]
Therefore, the correct answer is choice C. Hope this helps!
