# Two problems

6 views (last 30 days)
Y Vineel on 12 Mar 2011
Commented: Rebeca link on 28 Feb 2017
Hi, I am a beginner. I have three probs. 1) How to input the default angle in degrees rather than in radians?
2) I defined a as shown and calculated det(a)
a =
1 2 3
4 5 6
7 8 9
>> det(a)
ans =
6.6613e-016
The ans should be zero but the output is a value very close to zero. But I want a zero. How do I do that?
3) How do I learn MATLAB? Should I read some book or should I just go through the help section one article after another?

Evgeny Pr on 12 Mar 2011
Hi!
2) You can use FIX(DET(a)) :)
3) Book - it is always helpful . The more sources of information - the better. :)
Rebeca link on 28 Feb 2017
Thanks was useful to me¡

Paulo Silva on 12 Mar 2011
1) Matlab functions like sin and others only use radians, you can do the conversion
2) That determinant gives me zero but your result might be a problem with the floating-point relative accuracy, you can round numbers in several ways like:
round(det(a))
floor(det(a))
or use
fprintf('%1.5f',det(a)) %1 is the number of digits on the left and 5 is the number of digits on the right of the .
Your result is very close to the eps
eps
doc eps
3)