Errors in "Mastering Excel"

I wanted to report the following error in "Mastering Excel."
I’m on a Nexus 6P Android 6.0.1 phone with latest updates.
Let me know if you need more information.

“TAN” and “TANH” sound the same.
Video of error (can’t hear sound):
Question found in “Level 16” or “Math and trigonometry functions”:

Thanks! In the future, I’ll post as you indicated in your last reply. Have a good evening!