Q. If $I$ is incentre of $\mathrm{\Delta}\ ABC,$ then $I$ is
A) $\frac{a\overrightarrow{\mathbf{a}} + b\overrightarrow{\mathbf{b}} + c\ \overrightarrow{\mathbf{c}}}{a + b + c}$
B) $\frac{a\overrightarrow{\mathbf{a}} + b\overrightarrow{\mathbf{b}} + c\ \overrightarrow{\mathbf{c}}}{\sqrt{a^{2} + b^{2} + c^{2}}}$
C) $\frac{1}{3}\lbrack\overrightarrow{\mathbf{a}} + \overrightarrow{\mathbf{b}} + \ \overrightarrow{\mathbf{c}}\rbrack$
D) $\frac{\overrightarrow{\mathbf{a}} + \overrightarrow{\mathbf{b}} + \overrightarrow{\mathbf{c}}}{a + b + c}$
Explanation
(a)
If $I$ is incentre of $\mathrm{\Delta}\ ABC$. Then ,
$I\ is\ \frac{a\overrightarrow{\mathbf{a}} + b\overrightarrow{\mathbf{b}} + c\overrightarrow{\mathbf{c}}}{a + b + c}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.