Q. Let f(x)=4x3−2x+1−2x2+5x.Find limx→∞f(x).Choose 1 answer:(A) 0(B) 5(C) −21(D) The limit is unbounded
Analyze behavior of numerator and denominator: To find the limit of the function f(x) as x approaches infinity, we need to analyze the behavior of the numerator and the denominator separately. We will look for the highest power of x in both the numerator and the denominator to simplify the expression.
Divide by highest power of x: The highest power of x in the numerator is x2, and in the denominator, it is x3. To simplify the limit, we can divide both the numerator and the denominator by x3, which is the highest power of x in the denominator.
Simplify the expression: Dividing each term in the numerator and the denominator by x3 gives us:f(x) = [(−2x2/x3)+(5x/x3)]/[(4x3/x3)−(2x/x3)+(1/x3)]Simplifying each term, we get:f(x) = [(−2/x)+(5/x2)]/[4−(2/x2)+(1/x3)]
Terms with x in denominator approach zero: As x approaches infinity, the terms with x in the denominator will approach zero. Therefore, (−x2), (x25), (x22), and (x31) will all approach zero.
Evaluate the limit: After the terms with x in the denominator approach zero, we are left with: x→∞limf(x)=40
Final result: Simplifying the expression, we get: limx→∞f(x)=0