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Expand (x+3)(2x+9)

(In terms of formatting, we'll use little x "x" to mean the algebraic variable, and big x "X" to mean multiply). When we see two sets of brackets written next to each other, such as (...)...
LB
Answered by Luke B. • Maths tutor
9355 Views

b) The tangent to C at P meets the coordinate axes at the points Q and R. Show that the area of the triangle OQR, where O is the origin, is 9/(3-e)

If I were to get the job, I would get a writing board to help explain this. But to approach this question, it's a good idea to draw the graph. You know that the tangent line is a straight line and as the x a...
SH
Answered by Sophie H. • Maths tutor
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A scalene triangle has base of 5cm. The angle opposite to the base is 63°, and a second angle is 72°. Find the area of the traingle

Using the sine rule it's possible to find the length opposite to the 72° angle. Therefore: 5/(sin63)=x/(sin72) x=5sin(72)/sin(63)=5.34 At this point, the third angle is needed. Since a triangle has a total s...
AL
Answered by Alessandro L. • Maths tutor
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The curve C has the equation y = 2e^x -6lnx and passes through the point P with x - coordinate 1. a) Find the equation to the tangent to C at P

y = (2e-6)x + 6
SH
Answered by Sophie H. • Maths tutor
6662 Views

Why is potential energy negative? What does that even mean?

This is really just a definition! When we ask what the potential energy of an object is, we are really asking what energy is available to be extracted. In the case of gravity: two objects separated by an inf...
BT
Answered by Ben T. • Physics tutor
23379 Views