Special characters issue on MacBook Air

Princessfairey wrote:

Characters do not respond correctly on the key board

That usually means you have the wrong input source active. Go to system settings > keyboard > text input > edit and check what is on the list. You should only have one item and it should be for your normal typing language, e.g. US, British, or ABC for English.

If you provide details about exactly what is not correct, we can probably tell you exactly which input source is wrong.

Hi,

Click in the text where you want to place the character, then choose Edit > Emoji & Symbols (or press Control-Command-Space bar). The Character Viewer appears where you clicked. You can drag it to the desktop if you want to keep it open as you work.

And:

• ∑ — Option + W.
• Π or π — Option + P / Shift + Option + P.
• ∆ — Option + J.
• ƒ — Option + F.
• Ω — Option + Z.
• ≈ — Option + X.
• √ — Option + V.
• ∫ — Option + B.