Question

iii) find derivative of cos 7x.cos 5x​

Answer 1

Step-by-step explanation:

cos 7x.cos 5x = y

dy/dx = -7sin7x.cos5x - 5sin5x.cos7x

Answer 2

Answer:

Mathematics is the study of numbers, shapes and patterns. The word comes from the Greek word "μάθημα" (máthema), meaning "science, knowledge, or learning", and is sometimes shortened to maths (in England, Australia, Ireland, and New Zealand) or math (in the United States and Canada). ... Numbers: how things can be counted.