Find the numerical value of each expression. (Round your answers to five decimal places.)
(a) cosh 9
(b) cosh(ln 9)

Solution:

The term Cosh means the hyperbolic cosine function which is defined as follows:

a) Cosh x = \(\frac{e^{x}+e^{-x}}{2}\)

Therefore Cosh 9 will be written as :

Cosh  9  = \(\frac{e^{9}+e^{-9}}{2}\)  

              = (8103.08393+ 0.00012341)/2

             =  4051.54190

b)Cosh(ln(9) = \(\frac{e^{ln9}+e^{ln(-9)}}{2}\)

      = ( 9 - 0.11111)/2

      = 4.44444

Find the numerical value of each expression. (Round your answers to five decimal places.)

Summary:

The numerical values of  expressions  Cosh(9) and Cosh(ln9) are 4051.54190 and 4.44444  respectively.