1st :The angle of depression 30° = the angle of elevation (from the truck to the height of the building.
2nd : 
cos 30° = (adjacent side)/(hypotenuse)
cos 30° = x/100, but cos 30°= (√3)/2
(√3)/2 = x/100 and x = (100√3)/2
and x = (50.√3) = 86.60 m
        
                    
             
        
        
        
Answer:Decreasing
Step-by-step explanation:
Focus only on the 8-10 interval for x. Note that for x=8 , y=1, for x=9, y=0 and for x=10, y=-1. Y is obviously decreasing for  .
 . 
 
        
             
        
        
        
Answer:

Step-by-step explanation:
The given equation is :

We need to solve it using inverse operations.
Subtract 5 from both sides of the equation.

So, the solution of the given equation is  .
.