Intimidated by trigonometry? A few minutes with Selraybob and that will all go away. Sel and his friends take all that twisted-up mathematical gobbledygook that the physics folks sling and make it simple. You might find yourself calling your old math teachers and giving them the growly-voiced what’s what. “Hey!” you might say. “Sine’s just a ratio!” But be nice. They’re still math folks. Free on Kindle.