Word Problem of the Week: Map the Ohio River

It's nice to see a little connection between geometry and geography.

From Graphic Algebra, by Andrew Wheeler Phillips and William Beebe, 1904

p. 8:

Draw a map of the Ohio River from the following latitudes and longitudes, which are reckoned from the Equator and the meridian of Washington respectively:

This is the earliest book I have seen that emphasizes graphing equations as an algebraic tool. Then, 80 years later, the graphing calculator is invented.

Word Problem of the Week: Problem of the Lights

From Elements of Algebra, by Charles Davies, 1854.
p. 162:

"Find upon the line which joins two lights, A and B, of different intensities, the point which is equally illuminated by the lights."

This is a great little simple sounding problem that lends itself, in this case, to three and a half pages of discussion of various cases. At the end of this, the author states that "the preceding discussion presents a striking example of the precision with which the algebraic analysis responds to all the relations which exist between the quantities that enter a problem." I should say so.