which exponential function goes through the points (1, 8) and (4, 521)?

Question

anonymous · Answer

f(x) = 4(2)^x
f(x) = 8(2)^-x
f(x) = 4(4)^-x
f(x) = 2(4)^x

anonymous · Answer

please help! ill give you medals

mathmale · Answer

You have at least two choices here:  one would be to substitute the coordinates of the two given points into each of the given possible answers and determine which one of the answers is a true equation.

The other approach would be to actually find the correct relationship yourself, using the model y=ax^b.  Should you decide to do the problem in this manner, you'd need to find the values of a and b.

Your choice.

anonymous · Answer

okay I got it, thank you

hero · Answer

I thought the general exponential formula was $y = ab^x$