Given y = x(3x+ 5)^3. Find dy/dx.

First we notice that y can be written as the product of two functions of x, u = x and v = (3x + 5)^3. This means we can use the product rule to differentiate which is dy/dx = uv' + vu'. We can plug our functions u and v into this formula, using the chain rule to differentiate v to arrive at dy/dx = (3x + 5)^3 + 9x(3x + 5)^2. Next we need to simplify by taking out a common factor to get (3x + 5)^2 ((3x +5) + 9x)). Which we can further simplify to (3x + 5)^2 (12x + 5) which is the final answer.

MS

Related Maths A Level answers

All answers ▸

How do you find dy/dx for a set of parametric equations?


Find the integral of the function y = ln(x)


The gradient of a curve is given by dy/dx = 3 - x^2. The curve passes through the point (6,1). Find the equation of the curve.


By expressing cos(2x) in terms of cos(x) find the exact value of the integral of cos(2x)/cos^2(x) between the bounds pi/4 and pi/3.