Question

the value of sin50-sin70+sin10 is equal to:-(a) 1 (b) 0 (c) 1/2 (d) 2

Answer 1

Given, sin 50 - sin 70 + sin 10

 = sin(60 - 10) - sin(60+10) + sin 10

Formula is Sin(a-b) = sin a cos b- cos a sinb, Sin(a+b) = sin a cos b + cos a sinb

= Sin(60) Cos(10) - Cos(60)Sin(10) - (Sin(60)Cos(10) + Cos(60)Sin(10)) + Sin(10)

=  -2*Cos(60) Sin(10) + Sin(10) 

=  -2*(1/2) * Sin(10) + Sin(10)

= 0

Hope this helps!

Answer 2

b 0 will be the answere