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How do you factorise a quadratic equation?

Often quadratic equations of the form a x 2 + b x+ c =0 can be easily solved by factorising. First, find pairs of numbers that multiply together to make c . Note that if c is positive, the two numbers will h...
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Answered by Matt M. • Maths tutor
5196 Views

If f(x)=7-4x, given that f(c)=9, find c

f(c) means let x=c. Remember that c is just an unknown number. The expression f(c)=9 means that when we put c through the function f(x)=7-4x, it gives the answer 9. Therefore we know 7-4c=9 is true. Now we h...
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Answered by Emma F. • Maths tutor
9665 Views

Find the tangent of the following curve, y=xe^x, at x=1 expressing it in the form y=mx+c?

Firstly, we calculate the y-value when x=1, namely y=e. Then we need to find the gradient of this curve at x=1, which can be determined by taking the derivative of y and then valuate it at x=1. So dy/dx=xe^x...
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Answered by Bruno S. • Maths tutor
18885 Views

given y=(1+x)^2, find dy/dx

There are two ways in which this we can do this, The first is explanding the brackets to get 1+2x+x 2 and differentiating to get 2+2x. The second way is using the chain rule , let u=1+x such that y=u 2 and d...
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Answered by Sam G. • Maths tutor
9192 Views

What is the best way to solve simultaneous equations?

The easiest way to solve simultaneous equations is to label the equations so you clearly follow them throughout. For example, say you are asked to solve the unknowns for the simultaneous equations 3x-y=8 and...
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Answered by Lucy W. • Maths tutor
6097 Views