"Lew Hodgett" writes:
Have fun.

Answer to follow.

Lew
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Let: a = b,

therefo

a = a

Then: (1) a^2 = ab,

a^2 == aa

(2) a^2 - b^2 = ab - b^2,

a^2 - a^2 = a^2 - a^2 (reduces to 0 = 0)

(3) (a + b)(a - b) = b(a - b),

(a+a)(a-a) = b(a-a)

Here you multiply by zero (so 0 = 0)

(4) a + b = b,

a+a = a

Demonstrably false.

(5) 2b = b,
(6) 2 = 1

It would seem that we have proved 2 = 1.

What is wrong here?

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From:

Basic Mathematics For Engineering And Science, Page 18, 1952

By:

Walter R Van Voorhis, PhD, Professor of Mathematics
Fenn College, Cleveland, Ohio

and

Elmer E Haskins, PhD, Professor of Mechanical Engineering
Fenn College, Cleveland, Ohio
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