the value of c for which so real value of x , the vector cxi^-6j^+k^ and xi^+2j^+2ck^ makes an obtuse angle = = = = Share with your friends Share 0 Manbar Singh answered this Since, cxi^ - 6j^ +3k^ and xi^ + 2j^ + 2cxk^ make an obtuse angle, we get cxi^ - 6j^ +3k^ . xi^ + 2j^ + 2cxk^ < 0⇒cx2 +6cx - 12 < 0⇒coefficient of x 2 <0 and discriminant < 0⇒c < 0 and 36c2+48c < 0⇒c < 0 and c3c+4 < 0⇒c should lie between -43 and 0⇒-43<c<0 1 View Full Answer
