Cos 157.5º=-cos (180º-157.5º)=-cos 22.5=-cos(45/2)
cos Ф/2=⁺₋√((1+cosФ)/2).
In this case 157.5º is in the second quadrant, therefore we use the following equation:
cos Ф/2=-√((1+cosФ)/2).          (we will have a negative number)
cos 157.5º=-cos (45/2)=-√((1+cos 45º)/2)
=-√((1+√2/2)/2)
=-√((2+√2)/4)
=-√(2+√2) / 2   (≈-0.92387...)
Answer: cos 157.5º= -√(2+√2) / 2
        
             
        
        
        
Answer:
-6
Step-by-step explanation:
 
        
             
        
        
        
Distance = 

so plug in the coordinates and you will get 14.14 units 
 
        
        
        
I’m pretty sure it’s -6 because f(x) is the first curve and g(x) is the second and there’s six spaces between each of their vertexes