2015年2月27日 · Basically this is a definition thing. pi is defined to be the ratio of the circumference of a circle over its diameter (or 2 times its radius). This ratio is a constant since …

2016年5月7日 · #0=2pir^2+2pirh-A#. If we take out the #2pi# and #h#, we get this simple equation: #0=r^2+r-A#. We know that #2pi#, #h#, and #A# are constants, so what we have …

2016年7月12日 · R= -h/2 +- sqrt(h^2/4 + a/(2pi) Notice we have a quadratic in R here: 2piR^2 + 2pihR - a =0 We can use the quadratic formula: R = (-2pih +-sqrt((2pih)^2-4(2pi)(-a ...

2016年1月1日 · See explanation... The circumference of a circle of radius r is of length 2pi r, by the definition of pi. If you dissect a circular disc into segments of equal size, you can …

2017年10月18日 · 26190 views around the world You can reuse this answer ...

2016年3月8日 · r=C/(2pi) This is the formula for Circumference C of a circle given the radius r, where pi=22/7 or 3.14 or 3.14159 or 3.1416.

2018年5月31日 · R = \frac{C}{2\pi} Isolate for R: Divide both sides by 2\pi : \frac{C}{2\pi} = \frac{2\piR}{2\pi} R = \frac{C}{2\pi}

2015年8月30日 · It is not arbitrary, but it is because of the definition of radian measure. One definition says the radian measure of angle theta is the ratio of arc length s to radius r when …

2018年3月23日 · Point P_1 At point P_1 the magnetic field due to the wire of radius a is directed to the left, and it has a magnitude of {mu_0 2I}/{2 pi r} = mu_0/pi I/r The point P_1 is at …

2017年2月11日 · See the entire solution process below: First, subtract color(red)(2pir^2) from each side of the equation to isolate the h term: S - color(red)(2pir^2) = 2pirh + 2pir^2 - …