
-

=x
You must find a common denominator(bottom)

×

=


-

=

Your answer is x=
Step-by-step explanation:

Use the identity

on the left side.
![\dfrac{1 - \cos [2(\frac{\pi}{4} - \alpha)]}{2} = \frac{1}{2}(1 - \sin 2\alpha)](https://tex.z-dn.net/?f=%20%5Cdfrac%7B1%20-%20%5Ccos%20%5B2%28%5Cfrac%7B%5Cpi%7D%7B4%7D%20-%20%5Calpha%29%5D%7D%7B2%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D%281%20-%20%5Csin%202%5Calpha%29%20)

Now use the identity

on the left side.


That is the definition of a irrational number, A rational number must be able to be written as a ratio of 2 integers. The denominator cannot be 0, because that would make the number undefined
Answer:
20
Step-by-step explanation:
25=50% so minus 5
Answer is D, this is easy.