Bolts are usually classified in terms of two types of measurements: the metric system and the imperial system. In calipers, the metric system is in units of millimeters, while the imperial system is in units of inches. For example, when a bolt is sized as 12 × 1.25 in the metric system, that means the bolt thread diameter measures 12 mm, and the thread pitch measures 1.25 mm.
So, if your metric bolt measures 0.78 over the threads, that means that the 
size of the bolt is 0.78 mm in thread pitch. The attached picture shows how you measure the thread pitch. 
 
        
        
        
Answer:
The relationship is not linear.
Step-by-step explanation:
 
        
             
        
        
        
Answer:
Increasing if f' >0 and decreasing if f'<0
Step-by-step explanation:
Difference quotient got by getting
 will be greater than 0 if function is increasing otherwise negative
 will be greater than 0 if function is increasing otherwise negative
Here h is a small positive value.
In other words, we find that whenever first derivative of a function f(x) is positive the function is increasing.
Here given that for x1, x2 where x1<x2, we have 
if f(x1) <f(x2) then the function is decreasing.
Or if x1<x2 and if f(x1) >f(x2) for all x1, and x2 in I the open interval we say f(x) is decreasing in I.
 
        
             
        
        
        
The angles are complementary meaning they =90 degrees.
So take (x-20) and x, and write this equation,
x-20+x=90
2x-20=90
move the 20 over
2x-20=90
    +20  +20
2x=110
x=55.
You can check it by plugging it back in,
(55-20)=35
and
x=55
35+55=90.
Thus, you know your answer is correct.