Question

sin 35sin 55-cos35cos 55=0​

Answer 1

sin35 sin55 - cos35 cos55

Step-by-step explanation:

LHS=

sin (90-55) sin 55 - cos(90-55) cos 55

{sin(90-A)=cosA}

{cos(90-A)=sinA}

cos55 sin55 - sin55 cos 55

=sin55 cos55 - sin55 cos55

=0 =RHS

Answer 2

sin35 . sin55 - cos35 . cos55

= sin(90-55) . sin55 - cos(90-55) .

cos55

= cos55 . sin55 - sin55 . cos55

= (sin55 . cos55) - (sin55 . cos55)

= 0

So sin35 . sin55 - cos35 . cos55 = 0