Answer:
- Josh's book lands first
- Ben's lands about 0.648 seconds later
Step-by-step explanation:
Using the given equation for v=60 and s=40, the height of Ben's book is ...
   h(t) = -16t² +60t +40
We want to find t when h(t) = 0, so we're looking for the solution to ....
   0 = -16t² +60t +40
Using the quadratic formula, we find the positive value of t to be ...
   t = (-60 -√(60² -4(-16)(40)))/(2(-16)) = (15 +√385)/8 ≈ 4.3277
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Similarly, the height of Josh's book is ...
   0 = -16t² +48t +40
   t = (-48 -√(48² -4(-16)(40)))/(2(-16)) = (12 +√304)/8 ≈ 3.6794
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The time before Josh's book lands is shorter by ...
   4.3277 -3.6794 ≈ 0.6482 . . . . . seconds
Josh's book reaches the ground first, by about 0.648 seconds.
 
        
             
        
        
        
Answer:
both negative because y is negative and make both answers negative
 
        
                    
             
        
        
        
Answer:
6765201
Step-by-step explanation:
(5.1*10)^4
51^4
6765201 (USED CALCULATOR)
 
        
             
        
        
        
Answer:
y = 90 -5/2 x
Step-by-step explanation:
The angle on the left equals x+3x+x = 5x
The angle on the right equals 2y
The two angles are same side interior angles which are supplementary because the lines are parallel
5x+2y = 180
Solving for y
2y = 180-5x
Divide by 2
2y/2 = 180/2 -5x/2
y = 90 -5/2 x
 
        
                    
             
        
        
        
I assume you're supposed to establish the identity,
cos(A) cos(2A) cos(4A) = 1/8 sin(8A) / sin(A)
Recall the double angle identity for sine:
sin(2<em>x</em>) = 2 sin(<em>x</em>) cos(<em>x</em>)
Then you have
sin(8A) = 2 sin(4A) cos(4A)
sin(8A) = 4 sin(2A) cos(2A) cos(4A)
sin(8A) = 8 sin(A) cos(A) cos(2A) cos(4A)
==>   sin(8A)/(8 sin(A)) = cos(A) cos(2A) cos(4A)
as required.