If f(x) = sin(2x)/(x^2) find f'(x)

As f(x) is in the form of u(x)/v(x) we can apply the rule that f'(x) = (u'(x)*v(x) - v'(x)*u(x))/(v(x)2), pulled from the C3 formula booklet.
If u(x) = sin(2x) then u'(x) = 2cos(2x).
If v(x) = x2 then v'(x) = 2x.
Hence, f'(x) = ((2cos(2x)*x2) - (sin(2x)*2x))/(x4)
(Will be easier to explain on a whiteboard w/ standard visualisation of functions)

LR

Related Maths A Level answers

All answers ▸

The polynomial f(x) is define by f(x) = 3x^3 + 2x^2 - 8x + 4. Evaluate f(2).


The graph with equation y= x^3 - 6x^2 + 11x - 6 intersects the x axis at 1, find the other 2 points at which the graph intersects the x axis


Solve the following equation for k, giving your answers to 4 decimal places where necessary: 3tan(k)-1=sec^2(k)


Why does the chain rule work?