The formula for the circumference of a circle is C - 2 xer. Determine the circumference when the radius r is 10 cm. a. 100 cm
C. 20 cm
b. 20 cm
d. 100 cm

Write the expression in complete factored form. 5n_(c - 3) - n(c - 3) =

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) = .

Use the distance formula to find the distance between (-3,5) and (3,1)