Quiz:Equivalence of integration problems

1 Suppose $f$ is a function with a known antiderivative $F$. Which of the following is correct (and can be deduced using integration by parts)?

	Knowledge of an antiderivative for $x\mapsto f(x^2)$ is equivalent to knowledge of an antiderivative for $F$.
	Knowledge of an antiderivative for $x\mapsto xf(x^2)$ is equivalent to knowledge of an antiderivative for $F$.
	Knowledge of an antiderivative for $x\mapsto x^{2}f(x^2)$ is equivalent to knowledge of an antiderivative for $F$.
	Knowledge of an antiderivative for $x\mapsto x^{2}f(x)$ is equivalent to knowledge of an antiderivative for $F$.
	Knowledge of an antiderivative for $x\mapsto xf(x)$ is equivalent to knowledge of an antiderivative for $F$.

2 Suppose $f$ is a function with a known antiderivative $F$. Which of the following integration problems is not equivalent to the others?

	$\int f(\sqrt{x})dx$
	$\int xf(x)dx$
	$\int f(x^2)dx$
	$\int F(x)dx$

3 Suppose we know the first three antiderivatives for $f$, i.e., we have explicit expressions for an antiderivative of $f$, an antiderivative of that antiderivative, and an antiderivative of the antiderivative of the antiderivative. What is the largest nonnegative integer $k$ for which this guarantees us an expression for an antiderivative of $x\mapsto x^{k}f(x)$?

	0
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	2
	3
	4

4 Suppose we know the first three antiderivatives for $f$, i.e., we have explicit expressions for an antiderivative of $f$, an antiderivative of that antiderivative, and an antiderivative of the antiderivative of the antiderivative. What is the largest nonnegative integer $k$ for which this guarantees us an expression for an antiderivative of $x\mapsto f(x^{1/k})$? For simplicity, assume that we are only considering $x>0$.

	0
	1
	2
	3
	4
	5

5 Suppose $f$ has a known antiderivative $F$. Consider the problems of integrating $f(x^2),xf(x^2),x^{2}f(x^2)$. What can we say about the relation between these problems?

	All of these have antiderivatives expressible in terms of $F$.
	$f(x^2)$ has an antiderivative expressible in terms of $F$. The integration problems for the other two functions are equivalent to each other.
	$xf(x^2)$ has an antiderivative expressible in terms of $F$. The integration problems for the other two functions are equivalent to each other.
	$x^{2}f(x^2)$ has an antiderivative expressible in terms of $F$. The integration problems for the other two functions are equivalent to each other.
	All the integration problems are equivalent to each other, but none has a guaranteed expression in terms of $f$ and $F$.

6 Suppose $f$ is an elementarily expressible and infinitely differentiable function on the positive reals (so all derivatives of $f$ are also elementarily expressible). An antiderivative for $f^{″}(x)/x$ is not equivalent up to elementary functions to which one of the following?

	An antiderivative for $x\mapsto f^{″}(e^x)$, domain all of $\mathbb{R}$.
	An antiderivative for $x\mapsto f^{\prime }(e^x/x)$, domain positive reals.
	An antiderivative for $x\mapsto f^{‴}(x)(\ln x)$, domain positive reals.
	An antiderivative for $x\mapsto f^{\prime }(1/x)$, domain positive reals.
	An antiderivative for $x\mapsto f(1/\sqrt{x})$, domain positive reals.