Answer:
Same here. 
Step-by-step explanation:
I'm usually bored, that's why I mainly use this site.
:D
 
        
                    
             
        
        
        
Your going to have to use the distance formula for these questions which is the square root of (x sub 2 - x sub 1) + (y sub 2 - y sub 1). For number 1 your coordinates are (-5,5) and (1,-2). Substituting these values into the formula your answer for number 1 is 9.2.
        
             
        
        
        
Answer:
If you've learnt sin(A+B) = sinAcosB + cosAsinB,
sin(4u)
= sin(2u+2u)
= sin(2u)cos(2u) + cos(2u)sin(2u)
= 2 sin(2u) cos(2u).
 
        
             
        
        
        
Answer: The lenght of the missing side is 4 cm
Step-by-step explanation:
The correct question is:
<em>The perimeter of the rectangle is 20cm . One side is 6cm. What is the length of the missing side?</em>
So, to answer it we have to apply the next formula:
Perimeter of a rectangle = 2 width + 2 length
Replacing with the values given: (assuming that the side given is the length of the rectangle)
20 = 2(6) + 2x
Solving for x:
20 =12 +2x
20-12 =2x
8 =2x
8/2 =x
4=x
The length of the missing side is 4 cm
Feel free to ask for more if needed or if you did not understand something.  
 
        
                    
             
        
        
        
5 7/8 is the answer to the problem