Answer:    
 (-4,-7)
(4,7)
(-4,-5)
(1,-1)
Step-by-step explanation:
   
 
        
                    
             
        
        
        
Cos(A-B) = cosAcosB + sinAsinB
<span>
cos(</span>π/2 - θ) = cos(π/2)cosθ + sin(π/2)sinθ 
π/2 = 90°
cos(π/2) = cos90° = 0.        sin(π/2) = sin90° = 1
cos(π/2 - θ) = cos(π/2)cosθ + sin(π/2)sin<span>θ 
</span>
                   = 0*cosθ + 1*sin<span>θ  = </span>sin<span>θ
Therefore  </span>cos(π/2 - θ) = sin<span>θ
  
QED   </span> 
        
             
        
        
        
Um i would need more details 
But i thing you would add those together
        
             
        
        
        
Answer:
97
Step-by-step explanation:
Marcus is aiming for an A- (90-94 percent). The question states that there is another test awaiting that is worth 100 points. In order to find the answer to the question, you need to:
1.) Add 400 + 100, to show how many points there are in total.
2.) Use the answer choices and add it to 353.
88 + 353 = 441
93 + 353 = 446
97 + 353 = 450
3.) Find the percentage of the sums.
441/500 = 88%
446/500 = 89%
450/500 = 90%
Since Marcus is aiming for an A-, we can conclude that obtaining 97 points will help Marcus achieve an A-.