Question

Sin75. Sin25- Cos75.Cos25= Sin10​

Answer 1

Answer:

Probably it is sin90 and not sin10

Following Identities are used in solution

i) sin(90-A) = cos A

ii) cos(90-A) = sin A

where A is the angle

Sin75 = Cos25 from i)

Cos 75 = Sin25 from ii)

Therefore the Equation is

cos25.sin25 - sin25.cos25

= 1

which is equal to sin90