Rewrite with only sin x and cos x.

sin 2x - cos x

Question

Rewrite with only sin x and cos x.

sin 2x - cos x

zepdrix · Answer

Recall the `Sine Double Angle Identity`:$$\large \color{green}{\sin 2x=2\sin x \cos x}$$

Understand how you can use this to deal with the sin2x in your problem? :)

anonymous · Answer

here are the options

 2 sin x cos2x

 sin x

 cos x (2 sin x - 1)

 2 sin x

anonymous · Answer

no i don't understand?

zepdrix · Answer

$$\large \color{green}{\sin 2x}-\cos x$$Using the identity I pasted above we can rewrite our equation as,$$\large \color{green}{2\sin x\cos x}-\cos x$$
From here we can factor out a cosx from each term.
What would that give you? :o

anonymous · Answer

no the 3rd one

anonymous · Answer

right?

zepdrix · Answer

lol i have a feeling you're just guessing XD

anonymous · Answer

No i really think it's the 3rd one

zepdrix · Answer

Ok, good job :D ya it's the third one.