I'm new to using Wolfram Alpha for teaching, having switched from Maple.
When teaching calculus with Maple in our computer lab, I had students use the "changevar" command as a tool for gaining an intuition of what makes an appropriate substitution when discussing the integration by substitute method. For example,
takes the original integral and constructs a new integral in terms of the variable, U. The idea is to get students to experiment with various choices for U, see what works best, and perform the algebra/substitution details outside of class.
There is an analogous tool for integration by parts.
Are there similar commands in Wolfram Alpha?