By using studying graph of function, the correct option is the fourth option
What is a function
A function from A to B is a rule that assigns to each element of A a unique element of B. A is called the domain of the function and B is called the codomain of the function.
There are different operations on functions like addition, subtraction, multiplication, division and composition of functions.
Here,
For x 1, (Solid dot is given, so equality is maintained here),
At x = 1, y = -1.
This happens for the function y = -2x + 1
So for x 1, the function is y = -2x + 1
Now for x < 1, (Hollow dot is given, so the equality will not be maintained here ),
At x = 1, y = 1
This happens for y = -x + 2
So for x < 1, the function is y = -x + 2
So the function is
y = -2x + 1, x 1,
y = -x + 2, x < 1
Fourth option is correct
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