For this case we have that by definition of trigonometric relations of a rectangular triangle, that the sine of an angle is given by the opposite leg to the angle on the hypotenuse of the triangle. While the tangent of the same angle is given by the leg opposite the angle on the leg adjacent to the angle.
Then, according to the figure we have:

Answer:

Answer:
cos 60° = 1/2 because the angles are complements.
Step-by-step explanation:
Do you mean an extraneous solution? I will tell you what I think. To tell if a solution is extraneous you need to go back to the original problem and check if there actually is a solution or if the solution is actually right. If not then it is extraneous.