Find the Domain g(x) = natural log of x-x^2
Problem
Solution
Identify the restriction for the natural logarithm function. The argument of a logarithm must be strictly greater than zero.
Factor the quadratic expression to find the critical points where the expression equals zero.
Determine the roots of the inequality. The expression equals zero when
x=0 andx=1 These points divide the number line into three intervals:(−∞,0) (0,1) and(1,∞) Test a value from each interval to see where the inequality
x*(1−x)>0 holds true.
For
x=−1 (−1)*(1−(−1))=−2<0 (False)For
x=0.5 (0.5)*(1−0.5)=0.25>0 (True)For
x=2 (2)*(1−2)=−2<0 (False)
Conclude that the inequality is satisfied only in the open interval between the roots.
Final Answer
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