How would you use the trigonometric subtraction formula to verify this identity:

Question

anonymous · Answer

$$\sin(\frac{ \pi }{ 2 }-x)=cosx$$

zzr0ck3r · Answer

$\sin(\alpha-\beta)= \sin(\alpha)\cos(\beta)-\sin(\beta)\cos(\alpha)$

Using that we have

$\sin(\dfrac{\pi}{2}-x)=\sin(\dfrac{\pi}{2})\cos(x)-\sin(x)\cos(\dfrac{\pi}{2})=1*\cos(x)-\sin(x)*0=\cos(x)$

anonymous · Answer

Can you explain to me

zzr0ck3r · Answer

which part?

anonymous · Answer

=1∗cos(x)−sin(x)∗0=cos(x)

zzr0ck3r · Answer

They said you can use this formula

$$\sin(\alpha-\beta)= \sin(\alpha)\cos(\beta)-\sin(\beta)\cos(\alpha)$$

If we let $\alpha=\dfrac{\pi}{2}$ and let $\beta=x$ we get the above result.

zzr0ck3r · Answer

well what is 1*cos(x)?


what is 0*sin(x)?


what is cos(x) -0?

anonymous · Answer

Yeah , but why did you add that part ?

zzr0ck3r · Answer

add?

anonymous · Answer

Like why is that part there

unklerhaukus · Answer

http://openstudy.com/study#/updates/55d94ce2e4b05a670c276053

zzr0ck3r · Answer

I feel like there is an echo in here.