Question

find the inverse of the function
f(x)=x^2+x-7

Answer 1

What's keeping you from the usual "Swap and Solve" idea?

Note: It won't be pretty. The inverse will NOT be a function.

Answer 2

why?

Answer 3

x = y^{2} + y - 7 -- That was the Swap

Now, solve for y. Complete the square, Quadratic formula, whatever comes to mind.

Answer 4

y=x+7/y+1

Answer 5

??

Answer 6

That is not solving for y.

\(x = y^{2} + y - 7\)

\(y^{2} + y - (7+x) = 0\)

\(y = \dfrac{-1\pm\sqrt{1 + 4(7+x)}}{2}\)

No, THAT is solving for y. just like any other quadratic equation.