Ask your own question, for FREE!
Mathematics 8 Online
jknkjkjnjjjkl:

math problem

jknkjkjnjjjkl:

koolkidjay:

This might really help you hope this helps (https://www.desmos.com/calculator)

jknkjkjnjjjkl:

@florisalreadytaken

darkknight:

exponential form \[y=a*b^t\] given the point (2, 144) what do you think is the next step

jknkjkjnjjjkl:

y=2 times b^t

jknkjkjnjjjkl:

2*144^t

darkknight:

no,

darkknight wrote:
exponential form \[y=a*b^t\] given the point (2, 144) what do you think is the next step
also given y-intercept = 9, so (0, 9) now plug in 2 for t and 144 for y similarly in a different equation plug 0 for t and 9 for y you are trying to solve for a and b

jknkjkjnjjjkl:

144=a*b^2

jknkjkjnjjjkl:

(-infinity, infinity)

Florisalreadytaken:

this is the same as the problems we did earlier \( y=a(b)^x \) 1st point is \[ (2,144) \] \[ 144=a(b)^2 \] \[ a= \frac{144}{b^2} \] we plug that in the original formula -- also substitute the coordinates of the 2nd point in \[ 9= \frac{144}{b^2} \times (b)^0 \] \[ b= ? \]

jknkjkjnjjjkl:

4

Florisalreadytaken:

yeah, -4 takes no place.

Florisalreadytaken:

so, we know that \( b=4 \) thus, \[ a= \frac{144}{4^2} \] \[ a= ?? \]

jknkjkjnjjjkl:

9

Florisalreadytaken:

yes! \[ a= 9 \] \[ b=4 \] by plugging that info in the original formula, we get \[ \Large f(x)=9 \cdot 4^{x} \]

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!