# Need Urgent Trig Help!

• Mar 30th 2010, 03:30 PM
MathDumb
Need Urgent Trig Help!
Here is the question.

Q: Jasper walks 2km due west (270°). He then turns and walks 3km southeast (135°)

a) How far is Jasper from his starting point? Round your answer to the nearest 2 decimal places.

b) What is the direction of Jasper's destination in relation to his starting point? Round your
• Mar 30th 2010, 04:02 PM
masters
Quote:

Originally Posted by MathDumb
Here is the question.

Q: Jasper walks 2km due west (270°). He then turns and walks 3km southeast (135°)

a) How far is Jasper from his starting point? Round your answer to the nearest 2 decimal places.

b) What is the direction of Jasper's destination in relation to his starting point? Round your

Hi MathDumb,

I'll set up the first part for you.

Walking 2 miles due West and then turning 135 degrees southeast will make a 45 degree angle with the due West line.

This is the included angle between distances 2 and 3.

The third side of the triangle represents the distance he is from his original starting point.

Use law of cosines to determine this value.

$\displaystyle c^2=a^2+b^2-2ab \cos C$

$\displaystyle c^2=2^2+3^2-2(3)(2)\cos 45$
• Mar 30th 2010, 04:10 PM
MathDumb
Thank you so much. I worked out the problem and got an answer of 4.51 Km. Thank you so much again!
• Mar 30th 2010, 04:29 PM
MathDumb
For part B I got 28 degrees before subtracting anything. Like so:

SinC/c = SinA/a

Sin45/4.51 = SinA/3

3Sin45/4.51 = SinA

= 28 Degrees. Do I go any further from here?