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Why is it that sin^2(x) + cos^2(x) = 1?

Let's start with the definition of sin( x ) and cos( x ). We're going to use t rather than x here to avoid confusion, but the idea is exactly the same. Take a unit circle - that is, a circle with centre (0,0...
JT
Answered by John T. • Maths tutor
7695 Views

Prove that 0.565656.... can be expressed as 56/99.

1) Let x=0.565656... 2) Thus 100x=56.565656... 3) Subtracting equation 1) from 2) gives: 99x=56 4) Rearrange for x: x=56/99, Also x=0.565656... from 1) Therefore 0.565656...=56/99
DC
Answered by Daanyaal C. • Maths tutor
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How do I sketch a graph of a polynomial function?

To sketch a polynomial function (a polynomial is a function involving powers of x, for example y = x 3 + 2x 2 - 13x + 10): 1. Start by differentiating the function to find its turning points (where the first...
RA
Answered by Rose A. • Maths tutor
9668 Views

Find dy/dx for y=5x^3-2x^2+7x-15

Step 1: To differentiate an equation there is a simple rule to follow. For y=ax n dy/dx=anx n-1 . so for an example y=x 3 , dy/dx=3x 2. Therefore we just apply this rule into our equation. Step 2: Break the ...
MT
Answered by Matthew T. • Maths tutor
13414 Views

Solve the equation ((2x+3)/(x-4))-((2x-8)/(2x+1))=1

Step 1: Multiply everything by x-4 to give (2x+3) - ((2x-8)(x-4)/2x+1)=(x-4) Step2: Multiply everything by 2x+1 to give (2x+3)(2x+1)-(2x-8)(x-4)=(x-4)(2x+1) Step 3: Multiply out the brackets to give (4x 2 +8...
MT
Answered by Matthew T. • Maths tutor
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