#Forces problem key
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can anyone help me understand why in the matrix she is no longer multiplying x and y times f1 and f2
like its there when she writes down f1 f2 and f3 but then in the matrix its gone
coefficient matrix
F1, F2 and F3 are vectors which were written in coloumns
x and y refer to the components of that vector
i dont get it i thought the variable is x and y
so shouldnt the matrix output x and y
also i thought it was f1 times cos(tan...) plus f2times cos(tan...) 0 not without teh Fs
the rows have variables x and y
the coloumns have the force variables f1, f2 and f3
how does that work
could you write it llike a system
imagine like
4f1 + 4f2 + f3
5f1 + 4f2 + 2f3
then we can write the system into a **coefficient **matrix
f1 f2 f3
(4 4 1) x
(5 4 2) y
You know like Ax = b
the vector x would be your (x,y) basically
Where is z
lemme use other variables
so how do u know wha ti toutputs
cuz theres only 2 spots for answers
it gives x = and y= right
how does she get the answer from that
you know polar coordinate
x = cos(theta)
y = sin(theta)
here take a look
,w {{-cos(arctan(24/7)),cos(arctan(24/10))},{sin(arctan(24/7)),sin(arctan(24/10))}}{{x},{y}}={{0},{15}}
,w {{N[-cos(arctan(24/7))],N[cos(arctan(24/10))]},{N[sin(arctan(24/7))],N[sin(arctan(24/10))]}}{{x},{y}}={{0},{15}}
here you see the approximated values
It would have been better if your teacher did a straight line
the output are the forces f1 and f2
I mistakenly wrote (x,y) but it should have been (F1, F2) sorry for the confusion
,w {{N[-cos(arctan(24/7))],N[cos(arctan(24/10))]},{N[sin(arctan(24/7))],N[sin(arctan(24/10))]}}{{F1},{F2}}={{0},{15}}