pi X radius squared X the percent of the circle.
Radius 10, area = 100 pi; radius 9, area = 81 pi
No. But it's very convenient, and so close to 'pi' that it's often perfectly good enough for the purpose. In fact, it's amazing how close (22/7) really is ... it's larger than 'pi' by only about 0.04 percent !
((x*1.2)^2*pi-x^2*pi)/(x^2*pi)=0.44where X is the old radius((the new area - the old area) divided with the old area)The area increases with 44%
D=diameter... P=Pi(3.14159265)pi x D==================Divide the circumference by 'pi' to get the diameter.'Pi' is a number that can never be written exactly ... which is why a symbol is used instead. Its value is known to several thousand decimal places, which is more than anybody will ever need for any practical purpose.If you use [22/7] for 'pi', your answer is correct within 0.04 percent, which is pretty good.If you want the answer correct within one part in a million, use [3.14159] for 'pi'.
Assuming that this is 95 percent of a revolution, you can convert the percent to degrees by turning the percent into a decimal (.95) and multiplying that by the number of degrees in a circle (360) Degrees = 360 *.95 = 342 degrees Radians = Degrees * pi/180 Radians = 342 * pi/180 342 / 180 = 1.9 Radians = 1.9pi
Roughly 0.0000000462 percent, assuming that the sun radiates isotropically.Calculated as(pi) x (4000)2 / (4 pi) x (93,000,000)2
Multiply it by 4/3 pi r squared
pi X radius squared X the percent of the circle.
Radius 10, area = 100 pi; radius 9, area = 81 pi
If you mean percent error of 3.14 versus pi, which is 3.14159..., the error is only 0.05%
%g is more compact. Do some tests, for example:double pi= 3.1415926535897932384626433;printf ("%%f gives %f %f %f %f %f\n", pi, 100*pi, 10000*pi, 1000000*pi, 100000000*pi);printf ("%%e gives %e %e %e %e %e\n", pi, 100*pi, 10000*pi, 1000000*pi, 100000000*pi);printf ("%%g gives %g %g %g %g %g\n", pi, 100*pi, 10000*pi, 1000000*pi, 100000000*pi);%f gives 3.141593 314.159265 31415.926536 3141592.653590 314159265.358979%e gives 3.141593e+00 3.141593e+02 3.141593e+04 3.141593e+06 3.141593e+08%g gives 3.14159 314.159 31415.9 3.14159e+06 3.14159e+08
No. But it's very convenient, and so close to 'pi' that it's often perfectly good enough for the purpose. In fact, it's amazing how close (22/7) really is ... it's larger than 'pi' by only about 0.04 percent !
((x*1.2)^2*pi-x^2*pi)/(x^2*pi)=0.44where X is the old radius((the new area - the old area) divided with the old area)The area increases with 44%
(pi)(1/pi)=1.4396 ...
Percentage error = 100*error/standard = 100*(3.98-3.14)/3.14 = 100*0.84/3.14 = 84/3.14 = 26.75%
The MIRR of this project is 13.89% and the PI is 1.13.