Find dy/dx when y = x(4x + 1)^1/2

Here we can use the product rule where dy/dx = v du/dx + u dv/dx.We let u = x and v = (4x + 1)1/2 which means we get du/dx = 1 and by using the chain rule we get dv/dx = 1/2(4x + 1)-1/24 which simplifies to dv/dx = 2(4x + 1)-1/2.Plugging these results into the equation for the product rule we get: dy/dx = (4x + 1)1/2 + 2x(4x + 1)-1/2.This result can also be simplified by taking out a factor of (4x + 1)-1/2 to get dy/dx = (4x + 1)-1/2((4x+1) +2x) which proves thatdy/dx = (4x + 1)-1/2(6x +1). Remember that (4x + 1)-1/2 can also be written as the square root on the denominator of a fraction.

Answered by Rebecca N. Maths tutor

5069 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Express 2 cos x – sin x in the form Rcos( x + a ), where R and a are constants, R > 0 and a is between 0 and 90 ° Give the exact value of R and give the value of to 2 decimal places.


Integrate (x^2 +2)(2x-6) with respect to x.


7x+5y-3z =16, 3x-5y+2z=-8, 5x+3y-7z=0. Solve for x,y and z.


The gradient of the curve at A is equal to the gradient of the curve at B. Given that point A has x coordinate 3, find the x coordinate of point B.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences