Question

i) Sin 2A +Sin2B+ Sin 2CA - B) ​

Answer 1

Step-by-step explanation:

sin2A−sin2B+sin2C

⇒2cos(180−C)sin(A−B)+sin2C

=−2cosCsin(A−B)+2sinCcosC

=2cosC[−sin(A−B)+sin(180−A−B)]

=2cosC−sin(A−B)+sin(A+B)]

=2cosC×2cosAsinB

=4cosAsinBcosC