Given y=x^3+5x+3 find dy/dx when x=3

The question can be broken into two steps, 

1) dy/dx is asking to differentiate y=x3+5x+3 with respect to x

Differentiating we multiply by the current power and lower this powers value by 1. ( Constants differentiate to nothing )

i.e  x3 goes to 3x2

dy/dx=  3x2+5

2) Next we need to find the value of dy/dx when x=3 done simply by substituting all x's in the equation by 3

dy/dx=  3*(3)+ 5 = 32

RL
Answered by Robert L. Maths tutor

11737 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

What is Pythagoras' Theorem and how do I use it?


A) Multiply out 6(n - 2). B) Factorise psquared - 5p


How to convert worded problems to solvable inequalities.


(This was taken from a GCSE past paper)A bag of 24 spoons costs £19.95. A box of 18 forks costs £15.55. Bags and boxes cannot be split. Gregor decides to buy the same number of spoons as forks. He places an order to buy the smallest number of each


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:

© 2026 by IXL Learning