Math P1 doubt

[arlery]

June 2010 V1 Q. 10 (ii)

http://www.xtremepapers.me/CIE/Internat ... _qp_11.pdf

 

[sakibfaiyaz]

Find XO and XC
then use, required angle= cos^-1 {( XO.XC)/ (|XO|x|XC|)}........(i)

Solution :
XO = -2i -j -2k
XC = i -2j -k

XO.XC= 2
|XO| x |XC| = 3 x 6^1/2

using the formula given in (i),
Angle = 74.2

Hope it helps

 

[arlery]

Thanks ! I get it now.