Answer:
(a)  
(b) 
Step-by-step explanation:
It is given that  .
.
(a)
 
 
 
 
     ![[\because \sin x=\sin y\Rightarrow x=n\pi+(-1)^ny]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Csin%20x%3D%5Csin%20y%5CRightarrow%20x%3Dn%5Cpi%2B%28-1%29%5Eny%5D) 
 
(b)
 
 
 
 
 
 
         ![[\because \sin x=\dfrac{1}{\csc x}]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Csin%20x%3D%5Cdfrac%7B1%7D%7B%5Ccsc%20x%7D%5D)

Therefore,  .
.
 
        
             
        
        
        
Answer

Solution
Simplify both sides of the equation.

We are left with d = 4+
Add

Hence, d = 
 
        
             
        
        
        
Answer:

Step-by-step explanation:
Because vertical angles are always equal, we want to solve  .
.
We can add 10 to both sides to get  .
.
We can subtract  from both sides to get
 from both sides to get  .
.
Lastly, we divide both sides by 20 to get  .
.
So,  and we're done!
 and we're done!
The check is left as an exercise to the reader.
 
        
                    
             
        
        
        
This is the answer!! Also I use Photomath to help with my hw!