// calculus  derivatives
posted by Laura on .
y = sec(5x) / x^2
my notes say y' = 5x^2sec5xtan5x2xsec5x
i get y'= sec5x(2x^3)+sec5xtan5x(5)(x^2) when i change it to (sec5x)(x^2)
or by quotient rule
[ (x^2)(sec5x)(tan5x)(5)(sec5x)(2x) ] / (x^4)
which is correct?

yours is correct