Circumference of a circle - derivation
This page describes how to derive the formula for the circumference of a circle.
Recall that the definition of pi (π) is the circumference c of any circle divided by its diameter d. Put as an equation, pi is defined as
π
=
c
d
Rearranging this to solve for c we get
c
=
π
d
The diameter of a circle is twice its radius, so substituting 2r for d
c
=
2
π
r
If you know the area
Recall that the area of a circle is given by
area
=
π
r
2
Solving this for r
r
2
=
a
π
So
r
=
√
a
π
The circumference c of a circle is
c
=
2
π
r
<span>A. x = 2
Would make your statement true</span>
Now, there are 365 (excluding leap years) in a year, so, 275 days is not even a year, but is 275/365 of a year, or 55/73 of a year.
Answer:
y = -2x - 10
Step-by-step explanation:
Slope intercept form of equation is of form
y = mx+c
where m is the slope of line and c is the y intercept of the line.
Y intercept is point on y axis where the line intersects the y axis.
_____________________________
Given equation
y = -2x +4
comparing it with y = mx+ c
m = -2 , c = 4
_____________________________
when two lines are parallel, their slopes are equal.
Let the equation of new line in slope intercept form be y = mx + c
Thus slope of of new required line is -2
Thus m for new line is -2.
now, equation of required line : y = -2x+c
Given that this line passes through (-4, -2). This point shall should satisfy equation y = -2x+c.
Substituting the value of (-4, -2) we have
-2 = -2(-4)+c
=> -2 = 8 +c
=> -2 -8 = c
=> c = -10.
Thus , equation of required line is y = -2x - 10.
Answer:
b=16cm .......................
