They grouped Slide Over, Split View and Picture In Picture into one big group.
My mom has a 1st gen iPad Air and it, definitely, does NOT DO split screen view multitasking , at all.
Slide Over only.
OS 9 introduced the Split view multitasking mode.
If it wasn't available to certain iPads in iOS 9 or 10, it's NOT available in iOS 11!
Except from the iPad Users guides from iOS 9.3 and iOS 10.
“Split View
Keep two apps open and active at the same time (iPad Pro, iPad Air 2, iPad mini 4).”
Excerpt From: Apple Inc. “iPad User Guide for iOS 9.3.” Apple Inc., 2015. iBooks.
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Excerpt From: Apple Inc. “iPad User Guide for iOS 10.” Apple Inc., 2016. iBooks.
This material may be protected by copyright.
The ONLY place split view MAY work is when you have Safari open.
Apple implemented split screen multitasking view in Safari, so users can have two Safari web browser windows open at the same time
The iPad 5th gen can only do the Split screen view from within Safari
It can't split screen view with any other apps other than Safari
Perhaps the 1st gen iPad Air and other iPad Mini models CAN do split screen view from within Safari.
But do any other split screen view multitasking with any other apps, no.
I am the one who does all Apple and iDevice maintenance in my family and my mom's 1st gen iPad Air cannot do split screen multitasking with any other apps. Just does the smaller Slide Over view.