Help on precalculus plane vector problem

**lbj2322** · April 23rd 2009, 08:51 PM

A plane travels 170 miles at a heading of N 41 degrees W. It then changes direction and travels 165 miles at a heading of N 70 degrees W. How far is the plane from its original position?

**Prove It** · April 23rd 2009, 08:55 PM

Originally Posted by lbj2322

A plane travels 170 miles at a heading of N 41 degrees W. It then changes direction and travels 165 miles at a heading of N 70 degrees W. How far is the plane from its original position?

Hint: Draw a picture.

You should end up with a triangle with $a = 165\textrm{miles}$ and $b = 170\textrm{miles}$ , and the angle between them $C = 151^{\circ}$ .

Use the cosine rule to find $c$

$c^2 = a^2 + b^2 - 2bc\cos{C}$ .

**lbj2322** · April 23rd 2009, 09:08 PM

wouldnt the angle between them have to be obtuse?

**lbj2322** · April 23rd 2009, 09:21 PM

angle is actually 151 but thanks for giving me an idea of what to do

**Prove It** · April 23rd 2009, 10:20 PM

Originally Posted by lbj2322

angle is actually 151 but thanks for giving me an idea of what to do

Yes it is sorry, that was a typo... Fixed.

Thread: Help on precalculus plane vector problem

LinkBack

Thread Tools

Display

Help on precalculus plane vector problem

Similar Math Help Forum Discussions

Vector Plane Problem

Vector Plane Problem

Vector Problem - Plane and normal

Find Unit vector parallel to xy plane and perp. to a vector

Help with easy Vector/Line/Plane problem

Search Tags