Prove that:
Sin x - Sin 3x + Sin 5x - Sin 7x
= Cot 2x
Cos x-Cos 3x - Cos 5x + Cos 7x​

When y’all answer can y’all explain too !

The amount of calories consumed by customers at the chinese buffet is normally distributed with mean 2743 and standard deviation 652. one randomly selected customer is observed to see how many calories x that customer consumes. round all answers to 4 decimal places where possible. a. what is the distribution of x? x ~ n(correct, correct) b. find the probability that the customer consumes less than 2355 calories. incorrect c. what proportion of the customers consume over 3026 calories? incorrect d. the piggy award will given out to the 1% of customers who consume the most calories. what is the fewest number of calories a person must consume to receive the piggy award? incorrect calories. (round to the nearest calorie)

Mrs. robinson bought a novel at a bookstore on sale for 20% off its regular price of $29.99. mr chang bought the same novel at a different bookstore for 10% off its regular price of $25. which person received the better discount?