William021
New member
- Joined
- Feb 6, 2021
- Messages
- 4
Determine an exponential function that passes through the points (-3,7), (4,1.5).
f(x)=ab^x
I substitute both points to get these:
7=ab^-3
1.5=ab^4
I solve for A in 1st equation in terms of b:
7=ab^-3
a=7/b^-3
a=7b^3
I substitute A into second equation to solve for b
1.5=7b^3b^4
1.5=7b^7
b=0.80246
Now that I have B, I plug B back into a=7b^3 to get my A value:
a=7(0.80246)^3 = 3.61716
a=3.61716
answer: f(x)=.80246(3.61726)^x
But my graph looks like this:
Doesn't go through the desired points... I've checked and rechecked the math, but obviously I am missing something.
f(x)=ab^x
I substitute both points to get these:
7=ab^-3
1.5=ab^4
I solve for A in 1st equation in terms of b:
7=ab^-3
a=7/b^-3
a=7b^3
I substitute A into second equation to solve for b
1.5=7b^3b^4
1.5=7b^7
b=0.80246
Now that I have B, I plug B back into a=7b^3 to get my A value:
a=7(0.80246)^3 = 3.61716
a=3.61716
answer: f(x)=.80246(3.61726)^x
But my graph looks like this:
Doesn't go through the desired points... I've checked and rechecked the math, but obviously I am missing something.