What is the differential dy of y=sec(x^2-1) ?

1 Answer
Mar 21, 2018

#y'=2xsec(x^2-1)tan(x^2-1)#

Explanation:

We'll need the chain rule for this one:

We have...

#y=sec(x^2-1)#

By the chain rule...

#color(blue)(d/dx[sec(x^2-1)]=y'=f'(g(x))*g'(x)#

...and letting

#f(x)=sec(x)# and #g(x)=x^2-1#

So...

#f'(x)=sec(x)tan(x)#

#g'(x)=2x#

Thus...

#y'=sec(x^2-1)tan(x^2-1)*2x#