If a - 5b - 3 = 8, then the straight line ax + by + 3 = 0 must pass through the point I) (1, 5)
II) (1, -5)
III) (5, -1)
IV) (-1, 5)

The data represents the semester exam scores of 8 students in a math course. {51,91,46,30,36,50,73,80} what is the five-number summary?

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .

Seymour is twice as old as cassandra. if 16 is added to cassandra’s age and 16 is subtracted from seymour’s age, their ages become equal. what are their present ages? show !