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P is a point on a circle with the equation x^2 + y^2 = 45. P has x-coordinate 3 and is above the x axis. Work out the equation of the tangent to the circle at point P.

First insert x = 3 into the equation of the circle3^2 + y^2 = 459 + y^2 = 45 take 9 away from both sidesy^2 = 36 take the square root of both sidesy = 6 (not -6 as P is above the x-axis)Next find the grad...

Answered by Emily W. • Maths tutor

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Calculate the pH of a 0.0131 mol dm^-3 solution of calcium hydroxide at 10 degrees centigrade.

Multiply by 2 because calcium hydroxide = Ca(OH)2 so 2 x [OH-] per molecule.[OH-] = 0.0131 x 2 = 0.0262
Insert [OH-] value into the equilibrium equation along with the value of Kw at 10 degrees centi...

Answered by Emily W. • Chemistry tutor

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Explain why adding small amounts of acid or base hardly changes the pH of an acidic buffer solution.

An acidic buffer solution is made up of a weak acid (e.g. ethanoic acid) and a salt containing its conjugate base (e.g. sodium ethanoate). It resists pH change via two mechanisms: The fact that the acid i...

Answered by • Chemistry tutor

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The genetic code is described as degenerate, universal and overlapping. Explain these terms.

The genetic code is universal because all species use the same four bases A,T,C and G, and each base sequence codes for the same amino acid in all species. despite the 64 possible codons (sequence of thre...

Answered by Emily W. • Biology tutor

35670 Views

What is Stuart Hall's reception theory in regards to audience?

Stuart hall states that as the audience of a given piece of media text, there are 3 different ways to interpret said text. Producers generally encode a specific message or meaning within their product and...

Answered by Konstantina G. • Media Studies tutor

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