Respuesta :
Answer:
[tex]\pm 9in^2[/tex]
Step-by-step explanation:
We are given that
Radius of end of a log, r= 9 in
Error, [tex]\Delta r=\pm 1/2[/tex]in
We have to find the error in computing the area of the end of the log by using differential.
Area of end of the log, A=[tex]pi r^2[/tex]
[tex]\frac{dA}{dr}=2\pi r[/tex]
[tex]\frac{dA}{dr}=2\pi (9)=18\pi in^2[/tex]
Now,
Approximate error in area
[tex]dA=\frac{dA}{dr}(\Delta r)[/tex]
Using the values
[tex]dA=18\pi (\pm 1/2)[/tex]
[tex]\Delta A\approx dA=\pm 9in^2[/tex]
Hence, the possible propagated error in computing the area of the end of the log[tex]=\pm 9in^2[/tex]
Answer:
[tex]A = (254.34 \pm 28.26) in^2[/tex]
Step-by-step explanation:
radius, r = 9 inches
error = 0.5 inch
The area of the end is
A = 3.14 x r x r = 3.14 x 9 x 9 = 254.34 in^2
[tex]A = \pi r^2\\\\\frac{dA}{dr}=2\pi r\\dA = 2 pi r dr \\\\dA = 2 \times 3.14\times 9\times 0.5 = 28.26[/tex]
So, the area is given by
[tex]A = (254.34 \pm 28.26) in^2[/tex]