## Monday, October 23, 2006

### Need help solving the FoxTrot Su-Dork-U?

A week ago Sunday (10/15), the FoxTrot comic strip featured a Sudorku where the grid included various math equations (hence the Dork reference) in place of the usual starting digits.

It's pretty straightforward once you get the starting digits. For those that need some help, here are some clues:

• (1/3)^-1 is the reciprocal, namely (3/1)^1 or just 3

• For all the square roots, obviously only take the positive root

• d/dx 3x means take the derivative. In general d/dx ax^n = nax^(n-1). So you get 1*3*x^0 or just 3

• For the integral from 1 to 2, you do the reverse. x^2 becomes x^3/3. Taking this from 1 to 2 results in (2^3)/3 - (1^3)/3. That gives you 7/3. But it is multiplied by 3 to get you 7.

• 3! means factorial or multiplying all the numbers from 3 down to 1 (3*2*1) or 6.

• The sum of k from k=1 to 3, is just 1+2+3 = 6

• The log10(10) means that 10^x = 10. It's essentially the number of zeroes after the 1.

• 0101 is binary (base 2). This is 0*8 + 1*4 + 0*2 + 1*1 = 5

• By the Pythagorean theorem a^2 + b^2 = c^2. Some common Pythagorean triples are 3-4-5 and 5-12-13

• -(i^2). In complex numbers, i represents the square root of -1. So this is just -(-1) or 1.

• FF-F8 is a hexidecimal equation. In hex, A-F represent 10 through 15. So FF = 15*16 + 15 and F8 = 15*16 + 8. The difference is 7.

• sin(pi/2 radians) is the same as sin(90 degrees) = 1

• I'll post the solution in a later post...