Couple Questions about precalc CLEP

[Yung Bukket]

ok so my only experience with taking a CLEP is spanish but being prepared for it wasn't a problem because I grew up with spanish speaking parents.  Precalc however is a different story.  I'm good at math, I just want to make sure I spend my time studying stuff that's actually going to be on the exam.  In order to better prepare, I wanted to ask y'all a few questions:

1)  on the official site, they only offer the 2019 study guide.  I plan on taking the exam in 2018, will this be ok?

2)  has anyone used instantcert for precalc and found it useful?  The only posts I found about this are from years ago when precalc was new so instantcert wasn't very helpful back then.  I'm hoping that they've addressed this since then

Also, any additional study material suggestions would be greatly appreciated.  I know that if I study the right things I'll be fine, I just really want to make sure that is the case.  Thanks a lot guys, this forum is awesome