Can someone help I’m not good with word problems

I agree that this question can be confusing:

Apparently point A and point B must be on the same straight line (measured from the light house or the question would be nonsensical)

tan 13 = H / DA      where H is height of lighthouse

tan 8 = H / DB       tangent measured from point B

tan 13 / tan 8 = DB / DA

DB = .2309 / .1405 * 1279 = 2101 ft

DB - DA = 2101 - 1279 = 822.0 ft

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value