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Solve x^2+8x-5 = 0 by completing the square.

x² + 8x = (x + 4)² - 16, so x² + 8x - 5 = (x + 4)² - 16 - 5 = (x + 4)² - 21, so then (x + 4)²- 21 = 0 (x + 4)²= 21 -----> ...

Answered by Shadab J. • Maths tutor

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How do I begin analysing the unseen poem during the exam?

The idea of an unseen poem in an exam setting can be extremely unnerving- but if you set yourself up to feel comfortable reading and analysing poems you haven't studied before, you will have the tools to ...

Answered by Hannie P. • English tutor

5686 Views

Differentiate artanh(x) with respect to x

First we set y=artanh(x). Then we rearrange such that tanh(y)=x. There several approaches to find dy/dx, but the quickest is to use implicit differentiation.

The differential of tanh(y) is sech

Answered by Sam H. • Further Mathematics tutor

10628 Views

titration calculation: 35cm3 of Hydrochloric Acid reacts with 27.5cm3, 0.3mol/dm3 NaOH. What is the Concentration of the Hydrochloric Acid?

Write out what you know:

HCL - VOL: 35 --- CONC: (x) --- MOL: (x)
NaOH - VOL: 27.5 --- CONC: 0.3 --- MOL: (x)
Realise what you can work out - Mol of NaOH in ...

Answered by Ghazn K. • Chemistry tutor

4232 Views