## anonymous 5 years ago write a expotential function y=abx for a graph that includes (0,5)(2,45) please explain

1. anonymous

2. watchmath

Plugin $$(0,5)$$ we have $$5=a$$. Plug in $$(2,45$$ and $$a=5$$ $$45=5\cdot b^2$$ $$b^2=9$$ $$b=\pm 3$$ So $$y=5\cdot 3^x$$ or $$y=5\cdot (-3)^x$$

3. anonymous

well i think that you best take $b=3$

4. anonymous

$b>0, b\neq 1$

5. anonymous

reason being then you don't have to worry about something like $(-3)^{\frac{1}{2}}=\sqrt{-3}$

6. watchmath

Yes, just take b=3 :)