Hi,

I am trying to use asin to find out the degrees of an angle.
I have the following code but it always return 0.
double degreesToTurn;
degreesToTurn = asin(30);


Would anyone have any ideas why?

I have also try the sin function sothen i could pass the result to asin.

They both return 0.

Regards,
Giannis

The input value to "asin" needs to be in the range "-1 to +1". Otherwise the result is undefined. You're using 30 as the input!

It sounds like you're really wanting to turn an angle in radians (i.e. value 0 to 2*PI) to degrees (i.e. value 0 to 360). This is not what asin does!! Use the following formula for this conversion.

Hi,

I will try this but I have another question since i am completely new to C.

I am trying to do the following:

int i = 20;
int x = 30;

double w = i / x;

And I am not getting the same result.
Couldyou let me know why please?


Regards,
Giannis

C, and consequently ROBOTC, has some funny rules about calculation precisions and number bases. In the above 'i' and 'x' are both 'int' so "i / x' will be calculated using 'int' arithmetic and will result in '0'. The int value '0' will be converted to a 'float' and stored in 'w'.

You probably thought the result should be 0.66667 and were surprised with the zero value.

If you changed to

then you would get the fractional result. Because the cast of '(float)' applies to 'x' and then the calculation is performed with 'float' precision.