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A curve has the equation y=12+3x^4. Find dy/dx.

Bring the power down and multiply it to the value directly before x, and then remove 1 from the power after this. So in this instance 12 has no x or power with it, therefore it disappears because you multipl...
BP
Answered by Bradley P. Maths tutor
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Differentiate e^(xsinx)

Here you need to use the formula that the differential of e^f(x), where f(x) is any function, is equal to f'(x)e^f(x). So for our function we differentiate xsinx using product rule to give sinx + xcosx. By u...
SL
Answered by Samuel L. Maths tutor
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Show that sin2A is equal to 2sinAcosA

This question requires you to use the trigonometric identity sin(A+B)=sinAcosB + sinBcosA. The difficulty in this problem is noticing that you need to substitute 2A for A+A and then you can simply put this i...
SL
Answered by Samuel L. Maths tutor
39542 Views

If y = 2(x^2+1)^3, what is dy/dx?

Since the equation for y is a composite function (applying one function to another function) we need to use the chain rule to answer this question. Firstly let u = x^2+1 . This allows us to write y = 2u^3. D...
GC
Answered by Gemma C. Maths tutor
4690 Views

What is 'completing the square' and how can I use it to find the minimum point of a quadratic curve?

Completing the square is a process used to put a quadratic curve into a particularly nice form. The form we want is y(x) = r(x+s)^2 + t for some numbers r,s, and t. A 'general' quadratic we would expect to b...
TP
Answered by Thomas P. Maths tutor
5911 Views