Trig LCD: how did it go from sin(24*)cos(24*) to (1/2)sin(48*)?

[urimagic]

Hi friends,

I have a book with some study examples and I stumbled upon this sum, tried it myself, but then realized I have no clue as to where they get the part marked with a circle?

 

[jonah2.0]

Beer assisted recall follows.

Hi friends,

I have a book with some study examples and I stumbled upon this sum, tried it myself, but then realized I have no clue as to where they get the part marked with a circle?View attachment 35585

That's because of the identity

[imath]sin(2x)=2sin(x)cos(x)[/imath] or [imath]\frac{1}{2}sin(2x)=sin(x)cos(x)[/imath]

 

[urimagic]

Beer assisted recall follows.

That's because of the identity

[imath]sin(2x)=2sin(x)cos(x)[/imath] or [imath]\frac{1}{2}sin(2x)=sin(x)cos(x)[/imath]

Ahhh...Thank you kindly jonah2.0...do appreciate..!!

 

[Steven G]

If one expression is replaced with another expression, and there is no mistake, then you better believe that those two expressions are equal! You also have to realize that 48 = 2*24