
Verifying derivatives?
Can someone please help me.. I'm having no luck with help at all :( I really appreciated if someone would kindly help me with this.
The inverse secant function is often defined for x ≥ 1
by y=sec^{  1}x <=> sec y = x , 0 ≤ y ≤ π , y ≠ π/2
Verify that the derivative is correct for x > 1

Verify that what derivative is correct? You haven't given us anything to verify.
If $\displaystyle y= f^{1}(x)$ then $\displaystyle x= f(y)$ so that $\displaystyle \frac{df^{1}(x)}{dx}= \frac{dy}{dx}= \frac{1}{\frac{dx}{dy}}= \frac{1}{\frac{df}{dy}}$
Take the reciprocal of whatever formula you are given for the derivative of inverse secant and see if it looks like the derivative of secant.