IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => IGCSE/ GCSE => Math => Topic started by: kitty on May 12, 2009, 10:19:44 am

Title: Invariant line- Maths. HELP NEEDED URGENTLY.
Post by: kitty on May 12, 2009, 10:19:44 am

can somebody pls pls help? i dont know how 2 find the invariant line for a shear/stretch in transformation in maths. (stretch mainly). EXAM IS 2MORO!!!! pls help? ???

Title: Re: Invariant line- Maths. HELP NEEDED URGENTLY.
Post by: X Abdulrahman X on May 12, 2009, 05:59:00 pm

to find the invariant line, u take 1 point from a triangle, then another point but must be the one thats stretched, eg A and A2

A= (5.6)  A2=(5.12)
==(x,y)

X is invarient because it has not changed.


If it says multiply/stretch/shear triangle ABC for example by a number, and invarient line is Y, u do, for example the number is 3.

A=(5,  Y=(6x3)   ---   == A=(5,18), and u plot that point by A3 or w/e.

Title: Re: Invariant line- Maths. HELP NEEDED URGENTLY.
Post by: kitty on May 13, 2009, 05:19:51 am

Quote from: abdulrahman101 on May 12, 2009, 05:59:00 pm

to find the invariant line, u take 1 point from a triangle, then another point but must be the one thats stretched, eg A and A2

A= (5.6)  A2=(5.12)
==(x,y)

X is invarient because it has not changed.

thanx  :-\. but what if there are no points that lie on the same line? i got such a question once and the invariant line was diagonal. is there a formula of some kind that i can use? ???