A manufacturer of metal washers needs to determine the cross-sectional area of each washer. If the outer radius of the washer is R and the radius of the hole is r, express the area of the washer as a polynomial. Factor this polynomial completely.

Question

Mathematics

Kayley Boyer

18 April, 19:19

A manufacturer of metal washers needs to determine the cross-sectional area of each washer. If the outer radius of the washer is R and the radius of the hole is r, express the area of the washer as a polynomial. Factor this polynomial completely.

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Answers (1)

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Xander Wolf · Answer 1

The formula for area of any circle is : πr2.

To find the area of the washer, subtract the area of the hole from the area of the outer circle:

A = πR2 - πr2

A = π (R2 - r2)

Now factor completely:

A = π (R + r) (R - r)