SOLUTION: 1. Find the inverse of the function y = 4x – 7. Is the inverse a function? [] means square root.. thanks for your help 2. Find the inverse of y= [x+9].Is the inverse

Algebra ->  Rational-functions -> SOLUTION: 1. Find the inverse of the function y = 4x – 7. Is the inverse a function? [] means square root.. thanks for your help 2. Find the inverse of y= [x+9].Is the inverse       Log On


   



Question 180609: 1. Find the inverse of the function y = 4x – 7. Is the inverse a function?


[] means square root.. thanks for your help
2. Find the inverse of y= [x+9].Is the inverse a function?


Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
you find and inverse of a function by simple replacing all occurences of y with x and all occurence of x with y. A suggestion: use sqrt for square root instead of brackets...just a suggestion.
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y=4x-7 would become x=4y-7--->4y=x+7--->highlight%28y=%281%2F4%29x%2B%287%2F4%29%29
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y=sqrt%28x%2B9%29would become x=sqrt%28y%2B9%29-->x%5E2=y%2B9(squared both
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sides to eliminate radical)--->highlight%28y=x%5E2-9%29
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I graphed these so you could see what they look like graphed
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I got to thinking on the square root problem the range is limited by the square root. that is why on the graph you see only a 1/2 of a parabola. When we squared the radical to eliminate it we picked up extraneous roots which is why you see a full parabola on the graph of the inverse
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graph%28300%2C300%2C-10%2C10%2C-10%2C10%2C4x-7%2C%281%2F4%29x%2B%287%2F4%29%29
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graph%28300%2C300%2C-10%2C10%2C-10%2C10%2Csqrt%28x%2B9%29%2Cx%5E2-9%29