Identity for cos^4(x) through complex exponentials

Please buy this unique, available only here t-shirt: https://rb.gy/rmynnq This is a lovely exercise in getting an identity for the fourth power of cosine using complex exponentials. 1/5/2022, 10:40 AM NYT Please Check Out Our Merch below:)Your support truly counts and helps us to continue to make videos. Awesome Merch on Amazon: https://amzn.to/3PxqOFn T-Shirts You Will Enjoy: https://my-store-cf0bfb.creator-spring.com/ Free Amazon Music Trial: https://amzn.to/3OwefsL Free Audible Plus Trial: https://amzn.to/3b2L1UE Free Kindle Trial: https://amzn.to/3ony4aW