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How do you solve the simultaneous equations 3x + 4y = 5 and 2x – 3y = 9

We label each equation 3x + 4y = 5 (1) 2x – 3y = 9 (2) We now want to get rid of one of the variables (x or y). Lets get rid of x: We need (1) and (2) to have the same number of x's so we multiple (1) by 2 a...
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Answered by Sahiti S. • Maths tutor
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If x = cot(y) what is dy/dx?

Here we will use: cot(x) = cos(x)/sin(x) cosec 2 (x) = 1 + cot 2 (x) Chain rule : dy/dt * dt/ dx = dy/ dx Product rule : d/dx (u v) = u dv/dx + v*du/dx x = cot(y)= cos(y)/sin(y) dx/dy = -cos(y) ( cos(y) / si...
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Answered by Sahiti S. • Maths tutor
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Find the complex number z such that 5iz+3z* +16 = 8i. Give your answer in the form a + bi, where a and b are real numbers.

Firstly, we note that z being a complex number can be expressed in the form z = a + bi. If we then take the complex conjugate of this expression, the real numbers remain the same (as they are their own c con...
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What is the Current Account

The current account is a section in the Balance of Payments, which shows a country's transactions with goods, services and income. It is made up of four different parts. 1) The balance of trade in goods 2) T...
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Answered by Sahiti S. • Economics tutor
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What does dy/dx represent?

dy/dx represents the gradient of a curve. The d represents an infinitesimally small range so it is essentially as though you are doing change in y over change in x like you would for a y = mx +c graph but ov...
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Answered by Madeleine D. • Maths tutor
43556 Views