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The lamp has an efficiency of 20%. Explain what this means.

20% efficiency means that 20% of the electrical energy going into the lamp is transfered to light, and 80% of the energy is lost/wasted.
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Answered by Bryce P. • Physics tutor
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f(x)=2x^3-7x^2+4x+4, prove that (x-2) is a factor and factorise f(x) completely

if (X-2) is a factor, f(2)=0 2 2^3-7 2^2+4*2+4= 16-28+8+4=0 therefore (x-2) is a factor. 2x^3-7x^2+4x+4=(x-2)(2x^2-3x-2)=(x-2)(2x+1)(x-2)
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Answered by Bryce P. • Maths tutor
5257 Views

Find the derivation of (sinx)(e^2x)

Because there are two forms of x , the form uv'+vu' must be used. If y=sinx , dy/dx=cosx If y=e^kx , dy/dx=ke^kx Therefore dy/dx=(sinx)(2e^2x)+(e^2x)(cosx)
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Answered by Eric B. • Maths tutor
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Could you explain the distribution of the incidence of a tax and why it may fall differently on consumers and producers?

Firstly it would be useful to define terms and state that the majority of the time the tax in question will be a tax on a good or service for example the tax on cigarettes (tobacco). The reason that this que...
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Answered by Isaac V. • Economics tutor
2808 Views

Use logarithms to solve the equation 2^5x = 3^2x+1 , giving the answer correct to 3 significant figures.

Firstly, I would make sure that the student is aware of the basic conept of logarithims and run through the basic "laws" of logarithims to make sure that they have the knowledge they need to answer...
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Answered by Shubhayu G. • Maths tutor
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