Verify the identity cot(x-pi/2)=-tan x

Janie has $3. she earns $1.20 for each chore she does and can do fractions of chores. she wants to earn enough money to buy a cd for $13.50. write an inequality to determine the number of chores, c, janie could do to have enough money to buy the cd.

Which situation can be modeled by the inequality 5 + 10w ≥ 45? a. you start with $5 and save $10 a week until you have at least $45. b.you start with 5 baseball cards and purchase 10 cards every week until you have at most 45 cards. c.you start with 5 water bottles and purchases cases of 10 water bottles each until you have a total of 45 water bottles. d.you spend $5 plus $10 per week until you have less than $45.

Here are the coordinates for eight points on the coordinate plane (q > p > 0): a (0, 0), b (p, 0), c (q, 0), d (p + q, 0), e (0, q), f (p, q), g (q, q), and h (p + q, q). which four points, if any, are on the vertices of a square?