differentiate y=(4x^3)-5/x^2

to differentiate this equation we have to do it in two parts because there is a minus sign seperating them in the middle

for the first part we first have to multiple the constant by what the power of x is which is 3, secondly we have to minus 1 from the power

dy/dx = 3 x 4x3-1= 12x2

the second part is slightly harder as the x is on the bottom, to get around this we can write it as

y = 5/x^2 = 5x^-2

when the x is on the bottom it is the same as having the x on top with a minus sign infront of the power

we then do the same as in the first part which is multiple the constant at the front by the power above the x including the minus sign and minus one from the power

dy/dx = -2 x 5x-2-1 = -10x-3

we then have to combine the two halves of the equation without forgetting the minus sign in between which cancels out because there are now two negatives which equal a positive so we get

dy/dx = 12x2 + 10x-3

we can simplify this to

dy/dx = 12x+ 10/x3

this is the prefered form

as you can see we can swap the x with the minus power to the bottom to make it a positive power again

GK
Answered by George K. Maths tutor

5369 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

How do I calculate where a function is increasing/decreasing?


The straight line with equation y = 3x – 7 does not cross or touch the curve with equation y = 2px^2 – 6px + 4p, where p is a constant. Show that 4p^2 – 20p + 9 < 0.


Why bother with learning calculus?


Integrate exp(2x)cos(8x) by parts


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences