Hyperbolic functions

[HATLEY1997]

Where am I getting the half from?

 

[blamocur]

I cannot understand your writings. Your first line looks both wrong and irrelevant. How did you get it?

 

[Dr.Peterson]

You'll want to combine the sum and difference formulas for cosh. Try starting on the right rather than the left. (The 1/2 will be already there, but will go away.)

 

[HATLEY1997]

You'll want to combine the sum and difference formulas for cosh. Try starting on the right rather than the left. (The 1/2 will be already there, but will go away.)

Will try this thank you

 

[Steven G]

Just use this identity and the results follow immediately.
cosh(x) + cosh(y) = 2[cosh (x+y)/2 * cosh(x-y)/2]