What's the value of 36cos2a if tga=−√11?

Mathematics is the study of numbers, shapes, and patterns. It involves logical reasoning and problem-solving, and its principles are essential for many fields, such as engineering, medicine, and science. Mathematics is sometimes divided into pure mathematics, which studies abstract concepts, and applied mathematics, which focuses on practical applications. Math is used to analyze data and make predictions, and is used in the design and production of many products.