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Express cos(2x) in the form acos^2(x) + b, where a and b are constants.

we first remember the double angle formula, a really important formula. cos(2x) = cos 2 (x) - sin 2 (x).We know that sin 2 (x) + cos 2 (x) = 1, therefore, cos(2x) = cos 2 (x) + cos 2 (x) - 1. Giving our fina...
JP
Answered by Jack P. • Maths tutor
7136 Views

Find the values of x and y for which dy/dx = 0 in y= x^3 - 4x^2 - 3x +2

dy/dx = 3x 2 - 8x - 3 when dy/dx = 0 , 0 = 3x 2 - 8x - 3 Factorise : 0= (3x + 1)(x - 3) when 3x+1 =0 , x = -1/3when x-3=0 , x =3 so x = -1/3 , 3co-ordinates are : (-1/3, 68/27), (3, -16)
MC
Answered by Mahir C. • Maths tutor
6458 Views

Differentiate 2^x

2 x = e ln(2^x) = e xln(2) , d/dx(e xln(2) ) = ln(2)e xln(2) = ln(2)*2 x
TD
Answered by Tutor598438 D. • Maths tutor
4835 Views

y=4sin(kx) write down dy/dx.

let u=kx,du/dx=ky= 4 sin(u)dy/du= 4cos(u) dy/dx= du/dx*dy/du = 4kcos(u) =4kcos(kx)
WH
Answered by William H. • Maths tutor
3822 Views

Find the derivative of f(x) = 2xe^x

So with these kind of questions they tend to be more of a first part to a question, probably worth about two marks on an A Level exam.The first thing to spot with this question is that f(x) contains a produc...
FW
Answered by Fabian W. • Maths tutor
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