solving cosine rule

[Paul Ferris]

Another query, sorry.

I am trying to write a question involving the cosine rule and in the 'marking setting' entered the following;

sqrt({b}^2+{c}^2-2*{b}*{c}*cos(A))

It returned the correct answer ONCE then marking incorrect.  I am using random variables for b, c and A.  Note: it doesn't seem to matter if I place A in { } or not.  Basically i am just wanting to put the cosine rule formula in.

[Paul Ferris]

Problem solved.  I had forgotten to convert from degree to radians. :)