A) \[{{105}^{o}}\]
B) \[{{120}^{o}}\]
C) \[{{135}^{o}}\]
D) None
Correct Answer: B
Solution :
Sides are\[({{x}^{2}}+x+1),\,(2x+1),\,({{x}^{2}}-1)\]. The greatest side subtends the greatest angle. Hence \[{{x}^{2}}+x+1\] is the greatest side. Now \[\cos \theta =\frac{{{(2x+1)}^{2}}+{{({{x}^{2}}-1)}^{2}}-{{({{x}^{2}}+x+1)}^{2}}}{2(2x+1)({{x}^{2}}-1)}\] \[\Rightarrow \] \[\theta ={{120}^{o}}\].
You need to login to perform this action.
You will be redirected in
3 sec
