Let P=x^2-6x-13. If x is real, what is the smallest possible value of P?What value of x produces this minimum value of P?

If (a-2b)^2+(b-2)^2=0, and a and b are real, then what is ab?

1. The smallest possible value of P is -13, which occurs when x = 6.

2. ab = sqrt(2).