Which representation of a transformation on a coordinate grid does not preserve congruence?

(x, y) – $x, y)
(x, y) - (x + 17, y +17)
(x, y) - (x,-y)
(x, y) → (-X, -y)
PLS HURRY

Aheated piece of metal cools according to the function c(x) = (.5)x ? 7, where x is measured in hours. a device is added that aids in cooling according to the function h(x) = ? x ? 2. what will be the temperature of the metal after two hours?

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) = .

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m