You need to draw the triangle DEF with a right angle at E. Angle D = 40 and DE = 100 m. Once you have marked up your triangle, you can use cosine to find DF.
Answer:
∠LOA≅∠LMA
Step-by-step explanation:
The first two options are incorrect because you need one more set of congruent ANGLES, not SIDES. The last option would prove congruency, but through ASA, not AAS. So it would be the third option.
Answer:
Step-by-step explanation:
If you plot this point and the directrix on a coordinate plane, you can see that the directrix is 1/4 of a unit below the vertex. Since, by nature, a parabola opens in the direction opposite the directrix and "hugs" the focus, this is a positive x-squared parabola (meaning it opens upwards). The formula for this type of a parabola is, in vertex form,

where p is distance (in units) between the vertex and the directrix and h and k are the coordinates of the vertex. For us, p = .25, h = 7, and k = -6. Filling in our formula:

Simplify the left side to
which simplifies, in its entirety, to
