Is this a function or not need asap please taking a test✨

Which graph shows a function with a range of all real numbers greater than or equal to -1

Tanya has $42 to spend at the dolphin island store. tshirts sell for $7 each and a pair of sunglases sells for $6.tanya buys 3 tshirts. how many pairs of sunglases can she buys with the amount of money she has left

Cot(90° − x) = 1 the value of x that satisfies this equation is °. a. 60 b. 135 c. 225 d. 315