JEE MATHEMATICS MCQ: PROPERTIES OF TRIANGLES

1 Easy

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Application +4 | -1

In a

\Delta \,ABC

a\left( {{b^2} + {c^2}} \right)\,\,\cos \,\,A + b\left( {{c^2} + {a^2}} \right)\,\,\cos \,\,B + c\left( {{a^2} + {b^2}} \right)\cos \,\,C

is equal to

View answer and explanation

Correct option: C

3\,abc

The correct answer is C (

3abc

) because by using the projection rule, the given expression simplifies to

3abc

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