Answer:

Step-by-step explanation:
Given the differential (d/dx)(cos−1(x)), to find the equivalent formula we will differentiate the inverse function using chain rule as shown below;
let;


Therefore;

Since x = cos y from the above substitute;

Hence,
gives the required proof
Answer:
If the pool is 2/3 filled and then the inlet pipe and drain pipe are opened, it will take 140 hours to fill the pool
Step-by-step explanation:
An inlet pipe can fill the pool in hours = 20
Inlet pipe 1 hour work = 
A drain pipe can empty the pool in 21 hours
Drain pipe 1 hour work =
Inlet pipe and drain pipe 1 hour together work = 
Now we are given that the pool is 2/3 filled
So, remaining portion to be filled =
So, Inlet pipe and drain pipe fill
in hours = 1
So, they can fill 1/3 in hours = 
Hence If the pool is 2/3 filled and then the inlet pipe and drain pipe are opened, it will take 140 hours to fill the pool
Answer:
Step-by-step explanation:
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Answer:
98
Step-by-step explanation:
angles 1 and 2 are congruent, the lines in each side of the shape prove this.
another way to solve if you are not sure is to subtract all of the numbers from 360. all quadrilaterals equal 360 degrees, so if you subtract each of the three angles from 360, you will be left with the last angle.
360-120-44-98=98
Answer:
(10,10)
Step-by-step explanation:
coordinates are (x,y)
x is horizontal(left and right), y is vertical (up and down)
going down 6 means subtracting 6 from the second number
lets reverse that to go up and add 6 back
4+6=10
so the original point was (10,10)