Can someone help me!!!

I can't find revision for non-linear simultaneous equations anywhere! Could someone please explain for me how to do them or how to do them from a graph or tell me any revision sites with it on pleasee!

Reply 1

TheRandomer

What level are you at?

Higher GCSE

Is it one linear and one quadratic? Have you tried to bitesize website? www.bbc.co.uk/bitesize
Or google it. www.google.com

Reply 4

insparato

Heres one from C1 maths book.

2x + y = 1

x² + y² = 1

Okay as you know there are two ways to do simultaneous equations elimination and substitution. Substition is the only method that will work with quad sim equations.

Substitution involves the rearranging the subject to one equation to get x or y on its own. Most definately the linear equation is rearragned.

So change to get y on its own

y = 1-2x

now we are going to substitute this value for y into the quadratic equation.

x² + y² = 1

x² + (1-2x)² = 1

x² + 4x² - 4x + 1 = 1

5x² - 4x = 0

x(5x -4) = 0

x = 0 x = 4/5

sub the values x = 0 into

2x + y = 1

y = 1

sub value x = 4/5 into

2x+y = 1

2(4/5) + y = 1

y = 1 - 8/5

y = -3/5

So

x = 0 x = 4/5
y = 1 y = -3/5

hope that helps.