Question #e4ccd

2 Answers
Jun 11, 2017

((x,y),(-sqrt2, -1/sqrt2),(sqrt2, 1/sqrt2),(-3 sqrt3/4, -sqrt3/4),(3 sqrt3/4, sqrt[3]/4))

Explanation:

Making y = lambda x and substituting

{(x^2(1-lambda^2)=3/2),((1-lambda)/(1+lambda)=1/(6 lambda)):}

From (1-lambda)/(1+lambda)=1/(6 lambda) we obtain

lambda = {(1/3),(1/2):} and now substituting those results into

x^2=3/2 1/(1-lambda^2)->{(lambda=1/3->x=pm 3 sqrt3/4),(lambda=1/2->x=pmsqrt2):}

And now as y = lambda x we have:

((x,y),(-sqrt2, -1/sqrt2),(sqrt2, 1/sqrt2),(-3 sqrt3/4, -sqrt3/4),(3 sqrt3/4, sqrt[3]/4))

Jun 11, 2017

(+-sqrt(2),+-sqrt(2)/2) and (+-(3sqrt(3))/4,+-sqrt(3)/4)

Explanation:

Step 1. Use cross multiplication to eliminate fractions from the second equation.

(x-y)/(x+y)=x/(6y)

(x-y)6y=(x+y)x

6xy-6y^2=x^2+xy

6y^2-5xy+x^2=0

Think of this as a quadratic equation: ay^2+by+c=0.

Factoring gives

(2y-x)(3y-x)=0

or

y=1/2 x and y=1/3x

Step 2. Plug these linear equations for y back into the other equation. First, use y=x-:2

x^2-y^2=3/2

x^2-(1/2 x)^2=3/2

x^2-1/4 x^2=3/2

3/4x^2=3/2

x=+-sqrt(2)

Then use y=x-:3

x^2-(1/3x)^2=3/2

x^2-1/9x^2=3/2

8/9x^2=3/2

x=+-(3sqrt(3))/4

Step 3. Plug values of x back into y equations.

y=1/2x=1/2(+-sqrt(2))=+-sqrt(2)/2

y=1/3x=1/3(+-(3sqrt(3))/4)=+-sqrt(3)/4

ANSWER: (+-sqrt(2),+-sqrt(2)/2) and (+-(3sqrt(3))/4,+-sqrt(3)/4)