Prove that :
1/sin^2A -1/tan^2A =1

Find the solution of this system of equation -7x+y=-20 9x-3y=36

Someone answer asap for ! the boiling point of water at an elevation of 0 feet is 212 degrees fahrenheit (°f). for every 1,000 feet of increase in elevation, the boiling point of water decreases by about 2°f. which of the following represents this relationship if b is the boiling point of water at an elevation of e thousand feet? a. e = 2b - 212 b. b = 2e - 212 c. e = -2b + 212 d. b = -2e + 212

[tex]5 \times1 \frac{12}{13} [/tex] me