Answer:
Option B.
Step-by-step explanation:
By definition, the tangent of an angle is equal to
[tex]tan \theta = \frac {sin \theta}{cos \theta}[/tex]
We can replace sin and cos by their definitions
[tex]tan \theta = \frac {\frac {opposite}{hipotenuse}} {\frac {adjacent}{hipotenuse}}[/tex]
As we can check on the attached image, we are working on the unit circle, the hypotenuse is 1, the opposite side is y and the adjacent side is x. We can replace this on the formula above to get...
[tex]tan \theta= \frac {\frac {opposite}{hipotenuse}} {\frac {adjacent}{hipotenuse}} = \frac {\frac{y}{1}}{\frac{x}{1}}[/tex]
Finally, simplifying we get the final result...
[tex]tan \theta= \frac {\frac {opposite}{hipotenuse}} {\frac {adjacent}{hipotenuse}} = \frac {\frac{y}{1}}{\frac{x}{1}} = \frac{y}{x}[/tex]
