Given that d/dx(cosx)=-sinx show that d/dx(secx)=secx(tanx)

let y=sec(x) = 1/(cos(X)) = cos(x)-1

Thus dy/dx = -1(cos(x))-2(-sinx) = sin(x)/(cos(x))2

= 1/cos(x)  x  sin(x)/cos(x)

=sec(x)tan(x)

OD
Answered by Owain D. Maths tutor

12644 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

How would you express (11+x-x^2)/[(x+1)(x-2)^2] in terms of partial fractions?


A curve has equation y = 3x^3 - 7x + 10. Point A(-1, 14) lies on this curve. Find the equation of the tangent to the curve at the point A.


Show that (1 - cos(2x)) / (1 + cos(2x)) = sec^2(x) - 1


Find the normal to the curve y = x^2 at x = 5.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning