If the mean of the numbers 8, 9, 10, 11, and x is 12, then what is the value of x? A. 7

B. 12

C. 22

D. 38

Iwill give brainliest only if your correct the words subsequent and submerge both contain the prefix sub. based on this information, what does the prefix sub most likely mean? a) under or secondary b) true or verifiable c) tricky or difficult d) around or centered on

What two criteria are needed for triangles to be similar

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) = .