a. One way of defining sec^-1(x) is to say that y=sec^-1(x)sec(y)=x and 0y

Show that, with this definition,

d/dx(sec^-1(x))=1 / x sqrt(x^2-1)

b. Another way of defining sec^-1(x) that is sometimes used is to say that y=sec^-1(x)sec(y)=x and 0y, y/2. Show that, with this definition,

d/dx(sec^-1(x) = 1 / (absolute value (x)) sqrt(x^2-1)