How do you differentiate y=cosh^-1sqrt(x^2+1)?

1 Answer
Apr 12, 2017

The answer is =x/(|x|sqrt(x^2+1)

Explanation:

We need

(coshx)'=sinhx

cosh^2x-sinh^2x=1

sinh^2x=cosh^2x-1

Let rewrite the equation

y=cosh^-1(sqrt(x^2+1))

So,

coshy=sqrt(x^2+1)

Differentiating both sides

(coshy)'=(sqrt(x^2+1))'

sinhy*dy/dx=(2x)/(2sqrt(x^2+1))=x/sqrt(x^2+1)

dy/dx=1/sinhy*x/sqrt(x^2+1)

We calculate sinhy

sinh^2y=cosh^2y-1

=x^2+1-1=x^2

sinhy=|x|

dy/dx=x/(|x|sqrt(x^2+1)