TOUGH_Fiitjee

Prove that the determinant --

sin 2A sin C sin B
sin C sin2B sin A
sin B sin A sin2C

=0
where A,B,C are the angles of a triangle.

6 Answers

11
Gone.. ·

i did it by converting angles to sides..but can u do without it ??

24
eureka123 ·

I too ahve done this ques by that method only..so I dont know..but i will be intrested to see any new method

11
Gone.. ·

ya that method is long n tedious..:(

24
eureka123 ·

yup.very loong

1
Shreyan ·

write sin2A = 2sinAcosA = sinAcosA + sinAcosA

sinC= sin[pi - (A+B)] = sin(A+B) = sinAcosB + sinBcosA

and so on for all the terms..and then write it as a product of two determinants...that way its really easy...
but i'm really lazy...so not feeling like typing all that long stuff!! [3]

11
Gone.. ·

thanks shreyan..wid ur awesome method it can b done in 2 steps..:)

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