# Finding Range of a function Algebraicly

• Aug 31st 2010, 09:05 AM
dorkymichelle
Finding Range of a function Algebraicly
The problem says use algebra to find the range of each function, that means no graphs.
\$\displaystyle h(y)=y^2-2y-8\$\$\displaystyle
A(stands for all real numbers)=y^2-2y-8\$
Solve for Y
Now this is where I get confused...
\$\displaystyle A+8=y^2-2y\$
That's how far I've gotten, no matter how I subtract, add, divide, the \$\displaystyle y^2 or 2y\$, I can't solve for Y
I know this is prob. algebra stuff, but that's what gets me the most (Speechless)
• Aug 31st 2010, 03:30 PM
skeeter
one way to algebraically find the range of a function is to find the domain of the function's inverse.
• Aug 31st 2010, 08:59 PM
dorkymichelle
That's a good idea, and I'll keep the inverse method in mind.
But for this class, he hasn't gone over inverses yet, and he wants us to find the Range that specific way for the homework, where it's set to A and solve for Y.
i def. rather use the graph.