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# A2 Maths HELP watch

1. The circle with equation x^2+y^2=1 is stretched with scale factor 3 parallel to the x axis and with scale factor 2 parallel to the y axis. Write down the equation of the new curve

2. (Original post by superkillball)
The circle with equation x^2+y^2=1 is stretched with scale factor 3 parallel to the x axis and with scale factor 2 parallel to the y axis. Write down the equation of the new curve

3. (Original post by superkillball)
The circle with equation x^2+y^2=1 is stretched with scale factor 3 parallel to the x axis and with scale factor 2 parallel to the y axis. Write down the equation of the new curve

Or perhaps:

2((1/3X)^2+Y^2-1)=0

Cant remember, btw ignore the answer before. Casue its late and I'm tired.
4. Thanks a lot
5. Parametric equations are:

x = 3cost, y = 2sint

Manipulate those to get:

x^2/9 + y^2/4 = 1
4x^2 + 9y^2 = 36
6. (Original post by mikesgt2)
Parametric equations are:

x = 3cost, y = 2sint

Manipulate those to get:

x^2/9 + y^2/4 = 1
4x^2 + 9y^2 = 36
I dont understand how u do it
7. (Original post by superkillball)
I dont understand how u do it
Do you understand the parametric bit?

The manipulation goes like this:

x = 3cost, y = 2sint

cost = x/3 => cos^2(t) = (x^2)/9
sint = y/2 => sin^2(t) = (y^2)/4

But: sin^2(t) + cos^2(t) = 1
=> (y^2)/4 + (x^2)/9 = 1

Multiplying by 4*9 = 36

4x^2 +9y^2 = 36

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