How to solve the problem??

If,cscA+cscB+cscC=0 ,then show that(sumsinA)^2=sumsin^2A

1 Answer
Mar 23, 2018

Please see below.

Explanation:

(sumsinA)^2=(sinA+sinB+sinC)^2

= sin^2A+sin^2B+sin^2C+2sinAsinB+2sinBsinC+2sinCsinA

= sumsin^2A+2sinAsinB+2sinBsinC+2sinCsinA

= sumsin^2A+2sinAsinBsinC(1/sinC+1/sinB+1/sinA)

= sumsin^2A+2sinAsinBsinC(cscC+cscB+cscA)

= sumsin^2A+2sinAsinBsinCxx0

= sumsin^2A