i plotted a graph, & i have reversed its Y-axis. when i do curve fitting(cftool),i gave x & y values but the y axis get upside down. how can i fit the graph as i desired.(attached graph)

i plotted a graph, for the proper understanding i reversed the y_axis, but i can't fit the graph, during fitting the y-axis appears as before making reversal. i want to fit in both customize equation and cubic.polynomialy,along the curve as shown in the attached graph

[dpb]

No attachment but I don't think it really matters.

What matters is how you plotted the polynomial and/or what you're using to get the figure. If nothing else and you're not doing this repetitively, open the figure with the figure editor and make the change on the appropriate axis manually.