There are 2 poles of length 50m, and a cable 80m long is strung between the poles(assume it is in a parabola shape). The distance from the ground to the lowest point of the cable is 20m. What is the length between the 2 poles?
idk where to start
Unless there's something funny with the cable, it's likely to hang in a catenary rather than a parabola.
The Q said to ASSUME it hangs in a PARABOLIC shape.
I think the distance between the poles is sqrt 120 ..... I'll see if I can work out the solution.....
I am not sure how to include the length of the rope in the solution.....hmmmmm....
See diagram below:
given the zeroes, the equation is then
y = (x-0)(x-d)
y = x^2 - dx now sub in the vertex 1/2d, -30
-30 = (1/2d)^2 - d (1/2d)
-30 = 1/4 d^2 - 1/2d^2
-30 = -1/4 d^2
d^2 = 120
d = sqrt (120)