Given

To determine whether the function represents exponential growth or exponential decay, and the y-intercept.
now,
It is given that,

The exponential functions are of the form,

If a is positive and b is greater than 1, then it represents exponential growth.
And, if a is positive and b is greater than 0 and less than 1, then it represents exponential decay.
Since b=1/3<1.
Then, the given function represents exponential decay.
The y- intercept of the function is,

Hence, the y-intercept is 0.99.