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Further Mathematics
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If y=x^3+9x, find gradient of the tangent at (2,1).

To find the gradient of the tangent, we can differentiate to give dy/dx=3x^2+9. We can now put in x=2 to find the gradient at (2,1): 3(2)^2+9=21. Therefore the gradient is 21 at (2,1).

AM
2372 Views

Find the set of values of x for which (x+4) > 2/(x+3)

This is an example of an inequalities question from FP2. For this, we will need to use the tools learned in this chapter. To start with, it may be tempting to multiply both sides of the inequality by (x+3...

TD
10707 Views

Given that z = a + bj, find Re(z/z*) and Im(z/z*).

By definition z*  = a - bj.

We can write z/z* = ((a+bj)/(a-bj))*(a+bj)/(a+bj).

We calculate this to be z/z* = (a^2-b^2)/(a^2+b^2) + j(2ab)/(a^2+b^2).

Therefore, Re(z/z*) = (a^2-b^2)/(...

PJ
5623 Views

z = 50 / (3+4i). What is z in a+bi form?

Multiply by complex conjugate

z = 50 / (3+4i) * (3-4i) / (3-4i)

Rationalise

z = 50 ( 3 - 4i) / 25 = 6 - 8i.

IM
6713 Views

How do you find the matrix corresponding to a transformation?

Let's say that T is a transformation of the two dimensional plane. Remember that we have the two standard unit vectors (1,0) and (0,1). These are, respectively, the unit vectors pointing in the positive d...

RF
2392 Views

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