Question

I walked East 5 meters and turned Northward to reach Durham. Which was 10 meters. What angle did I make to turn to go to Durham? Use Cos-1 or inverse cosine to get your answer.

Answer 1

In order to use the cosine of the angle, you need the hypotenuse of the triangle. If East is the x direction, and North is the y direction, use
X^2 + y^2 to find the square of the hypotenuse.
Let me know if you need more help from there.

Answer 2

yes please I figured out that the side is 8 but I dont know how to use the cos-1 functions on the calculator can u help me out please thank you

Answer 3

Cos(theta) = h/x
theta = Cos-1(h/x)
So divide h (the hypotenuse) by x, then find on your calculator
the Cos with a -1 and just push it.

Answer 4

sorry .. it's x/h
Cos(theta) = x/h

Answer 5

thanks ill try it out

Answer 6

The hypotenuse doesn't equal 8.
The side is:
\[ \sqrt{5^2 + 10^2} = \sqrt{125} = 11.2\]

Answer 7

ok thank you...im not very good at this :(

Answer 8

Did you find the angle?

Answer 9

no im giving up :/ this is too hard for me

Answer 10

Wait.

Answer 11

okay

Answer 12

Divide 5 by 11.2
Then push the cos with a -1 button on your calculator.

Answer 13

You might have to press the 'shift' key on your calculator, then press Cos, if Cos with a -1 is written above the Cos button.

Answer 14

when I do that it sayd invalid imput

Answer 15

ok i ithink the answer is 63.49

Answer 16

That's correct! Congratulations.

Answer 17

when I round it off

Answer 18

oh wow your amazing!!

Answer 19

aww thnx so very much for helping me...I was going to give up but you didnt let me thnxx:) !!!!

Answer 20

You're Welcome!