Answer:

Step-by-step explanation:
We are given that endpoints of a diameter at the points (7,2) and (-9,5).
Center of the circle is the mid point of diameter
So, first find the mid point of diameter
Formula : 

Substitute the values in formula


So, center of circle = (h,k )=(-1,3.5)
To find length of diameter :




Length of radius = r = 
Standard form of the equation of the circle : 
(h,k )=(-1,3.5)

Equation of the circle : 
Equation of the circle : 
Hence the standard form of the equation of the circle with endpoints of a diameter at the points (7,2) and (-9,5) is 
Subtracting 7 and dividing by -3 on both sides shows us that y = -9
Answer:
All you have to do is remember the equation: 2 *pi * r
or d * pi
Step-by-step explanation:
2R and d are the same thing
Answer:
p = 8
Step-by-step explanation:
The n th term of an AP is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₉ = 4 + 5p and d = 5, then
a₁ + 8d = 4 + 5p, that is
a₁ + 8(5) = 4 + 5p
a₁ + 40 = 4 + 5p ( subtract 40 from both sides )
a₁ = 5p - 36
a₂ = 5p - 36 + 5 = 5p - 31
a₃ = 5p - 31 + 5 = 5p - 26
a₄ = 5p - 26 + 5 = 5p - 21
Given that the sum of the first 4 terms = 7p - 10, then
5p - 36 + 5p - 31 + 5p - 26 + 5p - 21 = 7p - 10, that is
20p - 114 = 7p - 10 ( subtract 7p from both sides )
13p - 114 = - 10 ( add 114 to both sides )
13p = 104 ( divide both sides by 13 )
p = 8