(Prove)
(Prove)
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The results of [1] and [2] are the same. Thus, this is linear system.
 
The results of [1] and [2] are the same. Thus, this is linear system.
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y(t)=x(t)^2
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[1]
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x1(t)--->[system]---->y1(t)=x1(t)^2---->*a  ---(1) a*x1(t)^2
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 +
x2(t)--->[system]---->y2(t)=x2(t)^2---->*b  ---(2) b*x2(t)^2
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(1)+(2)= a*x1(t)^2+b*x2(t)^2
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[2]
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x1(t)--->*a --- (3) a*x1(t)
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x2(t)--->*b --- (4) b*x2(t)
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(3)+(4)=a*x1(t)+b*x2(t) ---->[system]---->(a*x1(t)+b*x2(t))^2
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The results of [1] and [2] are not the same. Thus, this is non-linear system.

Revision as of 05:00, 12 September 2008

A linear function

we have seen is a function whose graph lies on a straight line, and which can be described by giving its slope and its y intercept

Linearity

If both system yield the same output function, this is called a linear system.


Prove

y(t)=2x(t)

[1]

x1(t)--->[system]---->y1(t)=2x1(t)---->*a ---(1) a*2*x1(t)

x2(t)--->[system]---->y2(t)=2x2(t)---->*b ---(2) b*2*x2(t)

(1)+(2)= 2ax1(t)+2bx2(t)


[2]

x1(t)--->*a --- (3) a*x1(t) x2(t)--->*b --- (4) b*x2(t)

(3)+(4)=a*x1(t)+b*x2(t) ---->[system]---->2(a*x1(t)+b*x2(t))=2ax1(t)+2bx1(t)

The results of [1] and [2] are the same. Thus, this is linear system.


y(t)=x(t)^2

[1]

x1(t)--->[system]---->y1(t)=x1(t)^2---->*a ---(1) a*x1(t)^2

x2(t)--->[system]---->y2(t)=x2(t)^2---->*b ---(2) b*x2(t)^2

(1)+(2)= a*x1(t)^2+b*x2(t)^2


[2]

x1(t)--->*a --- (3) a*x1(t) x2(t)--->*b --- (4) b*x2(t)

(3)+(4)=a*x1(t)+b*x2(t) ---->[system]---->(a*x1(t)+b*x2(t))^2

The results of [1] and [2] are not the same. Thus, this is non-linear system.

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