Answer:
Step-by-step explanation:
x² - 12x + a = (x + b)²
x² - 12x + a = x² + 2xb + b²
-12 = 2b and a = b²
b = -6
a = b² = 36
Answer:
C. 1/(x^2 +1) > 0
Step-by-step explanation:
The cube of a negative number is negative, eliminating choices B and D for certain negative values of x.
1/x^2 is undefined for x=0, so cannot be compared to zero.
The value 1/(x^2+1) is positive everywhere, so that is the expression you're looking for.
1/(x^2 +1) > 0
