It is known that y is the inverse proportional function of X, and when x = - 1, y = 2, find the functional relationship between Y and X, and find the value of X when y = - 1 | Math enthusiast | Mathematical art

It is known that y is the inverse proportional function of X, and when x = - 1, y = 2, find the functional relationship between Y and X, and find the value of X when y = - 1

Analysis: according to the definition of inverse proportion function, the expression is set, and then the coefficient is solved by undetermined coefficient method
Let the inverse scale function be y = K / X (K ≠ 0),
When x = - 1, y = 2, then k = - 2
∴y=-2/x．
When y = - 1, x = 2
So the answer is 2
Comments: this question examines the use of undetermined coefficient method to find the expression of inverse proportion function

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