(-2,5), (-1,8), (0,6), (1,6), (2,7) is function or not a function help

Prove sin2a + cos2a - 1 / sin2a + cos2a + 1 = 1 - tana / 1 + cota

At a local museum, the total price for one adult and one child is $11. mrs. smith paid for herself and her three children. she spent $19. record the system of equations to be solved and then find the price of an adult and child ticket using either elimination or substitution.

When steve woke up. his temperature was 102 degrees f. two hours later it was 3 degrees lower. what was his temperature then?