SOLUTION: Please help, I'm stuck! A machinist is to manufacture a circular metal disk with area 900𝜋 cm2 a) What is the ideal radius of such a disk? (gives exactly 900&#120

Algebra ->  Trigonometry-basics -> SOLUTION: Please help, I'm stuck! A machinist is to manufacture a circular metal disk with area 900𝜋 cm2 a) What is the ideal radius of such a disk? (gives exactly 900&#120      Log On


   



Question 1087689: Please help, I'm stuck!

A machinist is to manufacture a circular metal disk with area 900𝜋 cm2

a) What is the ideal radius of such a disk? (gives exactly 900𝜋 cm2
area)

b) If the machinist is allowed a tolerance of ± 10 𝑐𝑚2
in producing such a disk, by how much can the radius vary from the ideal radius found in part a)?

c) In terms of the 𝜀, 𝛿 definition of lim𝑥→𝑎 𝑓(𝑥) = 𝐿, what is x? What is 𝑓(𝑥)? What is 𝑎? What is 𝐿? What value of 𝜀 is given and what is the corresponding value of 𝛿?

Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!
a) +Area+=+pi%2Ar%5E2+ so +900pi+=+pi%2Ar%5E2+ —> +900+=+r%5E2+ —> +highlight%28r+=+30cm%29+
b) For a tolerance of +/- +10cm%5E2+, the Area A can fall in this range: (approx) +896.8%28pi%29cm%5E2+%3C=+A+%3C=+903.2%28pi%29cm%5E2 so the radius can vary over the range +sqrt%28896.2%29+%3C=+r+%3C=+sqrt%28903.2%29+cm
or approx. +29.937+%3C=+r+%3C=+30.053+ cm so that means the radius can vary approx. +-0.063+%3C=+v+%3C=+0.053+ cm from the ideal (v = variation from ideal).
c)
           x is the independent variable, I'd say it corresponds to 'r' in the above.
         f(x) is a function of x,  and it corresponds to Area in the above.
           a  is a constant that x approaches, (30cm)
           L  is the limit,   ( +900%28pi%29cm%5E2+ )
          The limit is defined such that for 0<|x-p|<delta,   |f(x) - L| < +epsilon+  for real epsilon%3E0 and real +delta+%3E+0.   My guess is +0+%3C+delta+%3C=+0.053cm+ and +0%3Cepsilon%3C=10cm%5E2+