We're trying to find the height of a mountain.(adsbygoogle = window.adsbygoogle || []).push({});

First we have the measured altitude of 2 points at 3000 m above sea level.

Then, these two points are 10,000 m apart on the same axis(x axis, z axis is pointed up)

point A--> (0,0,0)

point B-->(10000,0,0)

We're trying to find the height of the mountain, the top of the mountain is point P.

Direction cosines:

Rap:

cos theta x= .5179

cos theta y= .6906

cos theta z= .5048

Rbp:

cos theta x=-.3743

cos theta y=.7486

cos theta z=.5472

Anybody? I've been stuck on this for a LONG time.

edit: well let me show what i've done so far (isn't much)

all i've written out is:

rapx/rap=.5179

rapy/rap=.6906

etc

but where do i go from here? I've drawn out triangles for each APx, APy, APz and same for BP, but none of this tells me anything or lets me continue. Nor do i know how the 10,000 plays a role in the equations other than |Rap| + |Rbp| =10,000m

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Direction Cosines

**Physics Forums | Science Articles, Homework Help, Discussion**