What would the exponential equation be?

Question

(-1,1.25) and (3,0.032)

Thanks

Answer 1

y = a(b)^x

 

Since (-1, 1.25) is on the graph, 1.25 = a(b)^-1

Since (3, 0.032) is on the graph, 0.032 = a(b)³

 

From the first equation, a = 1.25b

 

Substitute into the second equation to get 0.032 = 1.25b⁴

 

                                                                b⁴ = 0.0256

 

                                                                b = (0.0256)^1/4

 

                                                                   = 0.4

 

So, a = 1.25b = 1.25(0.4) = 0.5

 

Therefore, y = 0.5(0.4)^x