Let ABC be an acute scalene triangle, O and H be its circumcentre and orthocentre respectively. Further, let N be the mid point of OH. The value of vector from −−→NA+−−→NB+−−→NC is?
A
0
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
−−→HO
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
12−−→HO
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
12−−→OH
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is C12−−→HO −−→HE=−−→NE−−−→NH⇒12−−→AH=12[−−→NB+−−→NC]−12−−→OH(HE⊥BC,AH⊥BC)⇒−−→HE∥−−→AHHE=Rcos(A),AH=2Rcos(A)⇒−−→HE=12−−→AHEmidpointofBC⇒−−→NE=12[−−→NB+−−→NC]NmidpointofOH⇒−−→NH=12−−→OH⇒−−→NH−−−→NA=−−→NB+−−→NC+−−−→OH)⇒−−→NA+−−→NB+−−→NC=−−→HO+12−−→OH=12−−→HO