can anyone tell me this, it's driving me crazy because it should be easy. here goes.

For a roation of the vector (x,y,z) ( in 3-space obviously) about an axis which is determined by an arbitrary unit vector U=(a,b,c) through a positive angle beta(@), prove that that transformation Matrix is defined as

[HTML] a^2(1-cos@)+cos@ ab(1-cos@)-csin@ ac(1-cos@)+bsin@

ab(1-cos@)+csin@ b^2(1-cos@)+cos@ bc(1-cos@)-asin@

ac(1-cos@)-bsin@ bc(1-cos@)+asin@ c^2(1-cos@)+cos@ [/HTML]