-Radical two (square root of two)/2
Because:
5pi/4 = 225 the reference angle for that is 45 degrees, cos 45 = Radical two (square root of two)/2 and because 225 is in quadrant three and only tangent is positive in quadrant 3, the cos is negative
        
             
        
        
        
Factor the quadratic equation (3x-4)(x+3). Then set the factors equal to zero. 
3x-4=0, solve to get 4/3 
x+3=0 x=-3
 
        
             
        
        
        
Answer:
240
Step-by-step explanation:
Hope its right, sorry if it isn't. 
 
        
                    
             
        
        
        
Answer:
-3/5-13i/10
Step-by-step explanation: