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

Qualification => Subject Doubts => IGCSE/ GCSE => Math => Topic started by: wassup on November 03, 2009, 11:52:47 am

Title: Maths help
Post by: wassup on November 03, 2009, 11:52:47 am: Can ne1 temme how to find d centre of rotation??
Title: Re: Maths help
Post by: Ghost Of Highbury on November 03, 2009, 12:02:28 pm: join the respective points in the image and the object..draw their perpendicular bisectors...the intersection point of the bisectors wud be the center..
Title: Re: Maths help
Post by: wassup on November 03, 2009, 12:06:50 pm: Quote from: A@di on November 03, 2009, 12:02:28 pm
join the respective points in the image and the object..draw their perpendicular bisectors...the intersection point of the bisectors wud be the center..

thanks
Title: Re: Maths help
Post by: wassup on November 03, 2009, 12:14:50 pm: one more thing

when v r asked to find the inverse of a matrix

for example

M= (1 5)
(3 2)

Determinant will be -13

So, M^-1 = 1/-13(2 -5)
(-3 1)

v hav to leave here only or calculate further???

M^-1 = (2/-13 5/13)
(3/13 1/-13)
Title: Re: Maths help
Post by: @d!_†oX!© on November 03, 2009, 12:16:25 pm: u can leave it there only or continue...both re accepted and given marks acc. to the mark scheme
Title: Re: Maths help
Post by: wassup on November 03, 2009, 12:18:19 pm: Quote from: @d!_†oX!© on November 03, 2009, 12:16:25 pm
u can leave it there only or continue...both re accepted and given marks acc. to the mark scheme

thanks