Pages

Wednesday, March 9, 2011

Perfect square trivia

12^2 = 144
21^2 = 441

13^2 = 169
31^2 = 961

Geometry Challenge

Take any parallelogram.  Construct squares on each side of the parallelogram.  Prove that the centers of the constructed squares form a square.

Tuesday, March 8, 2011

0.99999... = 1

Let x = 0.99999...

10x = 9.99999...

10x - x = 9.99999... - 9 = 9

9x = 9

x = 1

Do you believe?

Log problem

log 237.5812087593 = 2.375812087593 (approximately)

What is the pattern here?  Can you write an equation for this that 2.375812087593 solves?  The equation has exactly one other solution.  What is the other solution?  Can you prove that these are the only two solutions?

(This is beyond the scope of the SAT Reasoning Test, but is reasonably related to the SAT Math 2 subject test.)

Digits Problem

Each letter represents a digit.  Solve for the digits and numbers.

TWO + THREE + SEVEN = TWELVE