not only isnt it necessary, it isnt useful for your purposes either
ipads are good for web browsing, playing games, and maybe reading papers (although an ipad mini is too small for the latter, and you would be better off with printed copies anyway). They arent meant for writing things. Get an ultrabook instead.
dont get me wrong, I absolutely love my ipad air, but I'm not going to pretend it has much productivity value except for being able to read and annotate pdfs (which I think a mini is too small for personally, although others seem to find it ok). Mainly I just use it for web browsing and games, and a few lifestyle apps. It definitely isnt a content creation device, and writing up lecture notes on it would be ridiculous.