Function Inverse Calculator (Linear)

This function inverse calculator finds the inverse of a linear function of the form f(x) = mx + b, the related function that reverses it and sends each output back to the input that produced it. You enter three numbers: the slope m, the intercept b, and a value of x at which to evaluate the inverse. The calculator returns the inverse function itself, written as f-inverse(x) = (x - b)/m, the inverse evaluated at your chosen x, and a check that feeds that result back through the original f(x) to confirm it returns to x. To find a linear inverse by hand you swap input and output, then rearrange: subtract the intercept and divide by the slope. A linear function only has an inverse when its slope is not zero, because a horizontal line sends every input to the same output and cannot be reversed; enter m = 0 and the calculator will tell you no inverse exists. This tool suits algebra students checking homework, anyone verifying working by hand, and anyone wanting a fast, reliable answer without doing the algebra themselves. Try the defaults of m = 2 and b = 3 evaluated at x = 7 to match the worked example on the page, then swap in your own slope, intercept and x value to solve any linear inverse in seconds.

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