The circumference of a sphere was measured to be 74 cm with a possible error of 0.5 cm. Use differentials to estimate the maximum error in the calculated surface area. (Round your answer to the nearest integer.) cm2 What is the relative error?
Solution:
It is given that
Circumference of a sphere = 74 cm
Error = 0.5 cm
We know that
Circumference of a sphere C = 2πr
It can be written as
74 = 2πr
r = 74/2π = 37/π
C = 2πr
By differentiating with respect to r
dC / dr = 2π
dC = 2π dr
dr = dC / 2π = 0.5 / 2π
The formula to find the surface area of a sphere is
S = 4πr2
The maximum error in the surface area is
dS = 8πrdr
Here
On substituting the value of
dS = 8π × 37 / π × 0.5 / 2π = 23.5 = 24 cm2
The maximum error in the surface area is 24 cm2
We know that
Relative error = ΔS/S
ΔS/S = 8πrdr / 4πr2
ΔS/S = 2 dr/r
We can write it as
ΔS / S = 2 × [0.5 / 2π] / [37 / π]
ΔS / S = 2 × 0.5 / 2π × π / 37
ΔS/S = 0.014
Therefore, the maximum error in the calculated surface area is 24 cm2 and the relative error is 0.014.
The circumference of a sphere was measured to be 74 cm with a possible error of 0.5 cm. Use differentials to estimate the maximum error in the calculated surface area. (Round your answer to the nearest integer.) cm2 What is the relative error?
Summary:
The circumference of a sphere was measured to be 74 cm with a possible error of 0.5 cm. Using differentials the maximum error in the calculated surface area is 24 cm2 and the relative error is 0.014.
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