He probably mentioned only what he was interested in. What if you are interested in computer graphics, need to do a rotation, and need to understand why it did what it did? Also what about ham radio amateurs and anyone interested in waves? I am in both categories. Also let's say your second hobby is about drones and you want to know how signals are encoded, you need trigonometry. Also when someone beats you at mental arithmetic or you are being ridiculed for using your fingers to count, it can help to throw cos(π) to divert attention (just did that yesterday).
He probably mentioned only what he was interested in. What if you are interested in computer graphics, need to do a rotation, and need to understand why it did what it did?
Also what about ham radio amateurs and anyone interested in waves? I am in both categories.
Also let's say your second hobby is about drones and you want to know how signals are encoded, you need trigonometry.
Also when someone beats you at mental arithmetic or you are being ridiculed for using your fingers to count, it can help to throw cos(π) to divert attention (just did that yesterday).