Find the radius of a circle whose circumference is 538 units. r = 85.625 r = 85.669 r = 86.259

  r = 85.625 units

Step-by-step explanation:

This question is apparently designed to cause trouble.

  C = 2πr . . . . . formula for circumference

  r = C/(2π) . . . . solved for radius

  r = 269/π . . . . with the value of C put in

If you use an appropriately precise value for π, you get the answer shown above, 85.625. Here, "appropriately precise" means accurate to at least 5 digits. The value of π that gives the above result is 3.1416, accurate to 5 digits.

If you use a value of π accurate to only 3 digits, 3.14, the radius you obtain is 85.669. That 5-digit result cannot be relied upon when it is obtained using a 3-digit value for π. Unfortunately, many math problems (incorrectly) require the use of 3.14 for π, even when calculating results to 5 or 6 or 7 digits. In view of previous teaching, one cannot blame a student for making this selection.

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The choice r=86.259 uses a value of about 3.1185 for pi. That is not even close to any value that is ever recommended for use in a problem like this.

. + λrh() e 1 1 2 4 4 4 4 4 3 4 4 4 4 4 + th−1(− s(x)2 dx ω + λrh−1() e 2 1 2 4 4

step-by-step explanation: