PLZ HELP TIMED 20 POINTS! WILL MARK BRAINLIEST What is the equation of the graph below?

y = cosine (StartFraction x Over 0.4 EndFraction)
y = cos(5x)
y = cos(0.4x)
y = cosine (StartFraction x Over 5 EndFraction)

[15 points, algebra 2]simplify the complex fraction and find the restrictions.

72 the length of a side of a triangle is 36. a line parallel to that side divides the triangle into two parts of equal area. find the length of the segment determined by the points of intersection between the line and the other two sides of the triangle.

An observer(o) spots a plane(p) taking off from a local airport and flying at a 29 degree angle horizontal to her line of sight and located directly above a tower(t). the observer also notices a bird circling directly above her. if the distance from the plane(p) to the tower(t) is 6,000ft., how far is the bird(b) from the plane(p).