How on earth does theese examples get thoose answers?

[jespergreen]

Hi all.
I am teaching myself some statics and came across theese to examples in the (Danish) book.
The answer in degrees makes no sense at all.
Can you explain how the book gets thoose answers?



When i try to calculate i get totally different answers?

 

[mmm4444bot]

The answer in degrees makes no sense at all.
Can you explain how the book gets thoose answers?

cos(x) = 3613/3680

This equation tells us that symbol x represents an angle, and it also tells us that the cosine value for that angle is 3613/3680.

To find the measure of angle x, we use the inverse cosine function (aka: arccosine or cos^-1).

arccos(3613/3680) = 10.94995 degrees (rounded)

If you use a scientific or graphing calculator, make sure that it is set to work with angles in degrees.

If the calculator is working with radian measure, instead, it will tell you:

arccos(3613/3680) = 0.19111 :cool:

Same goes for the other example.

If tan(v) = 20,59/32,3 then v = arctan(20,59/32,3)

 

[jespergreen]

That makes sense now.
Thx a lot

 

[jespergreen]

Does the wiindows calculator support arccos/arctan etc?

 

[mmm4444bot]

From the calculator image, I cannot determine whether that version handles inverse trig functions.

Google "scientific calculator", to see Google's version and links to others (like this one).

Sometimes, you'll need to use a button to switch to inverse functions.

On Google's calculator, click the Inv button first. On Desmos' version, click on func.

 

[jespergreen]

Thank you.
I will try that