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integrate cos^2(2x)sin^3(2x) dx

To integrate this we need to use the chain rule, substituting cos2x = u Integral becomes: u 2 sin 3 2x dxChain rule: dy/dx = du/dx dy/du du/dx = -2sin2x --> dx = -1/2sin2x du Substituting into the equatio...
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Answered by Lucy W. • Maths tutor
7896 Views

Why does differentiation work like it does.

Differentiation is about the tangent at a point, from GCSE we have a formula to work out the gradient between two points, in other words, the gradient of the tangent. This means that as the two points get in...
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Answered by Lucas F. • Maths tutor
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(a) Express (1+4*sqrt(7))/(5+2*sqrt(7)) in the form a+b*sqrt(7), where a and b are integers. (b) Then solve the equation x*(9*sqrt(5)-2*sqrt(45))=sqrt(80).

(a) We can ‘get rid of’ a square root in the denominator simply by multiplying by 1 (value of the fraction stays unchanged) in a suitable form. We will take advantage of this formula: (a+b) (a-b)=a^2-b^2. So...
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Answered by Kristina B. • Maths tutor
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Find the equation of the tangent to the curve y=3x^2-7x+5 at the point (2, 3) .

The starting point for a question like this is to differentiate the function - in this case the curve y=3x 2 -7x+5 . We calculate that dy/dx=6x-7 . The question tells us that we are interested in the case wh...
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Answered by Matthew S. • Maths tutor
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Find the equation of the line perpendicular to the line y= 3x + 5 that passes through the point (-1,4)

Logically work through the problem: 1) Plot all the information that is available so you can visualise the problem better (always encouraged for graphical questions) 2) Understand that the gradient of the pe...
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Answered by Chagall C. • Maths tutor
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