Final answer:
The domain of f(x) is x>0, the y-intercept is (0,1), it is not always decreasing, the y-intercept is not (0,3)
Step-by-step explanation:
The function I(x) = 9/10^x represents an exponential function. Let's analyze each statement:
A. The domain of f(x) is x>0. This statement is true. In an exponential function with a positive base, like 10 in this case, the function is defined for all real numbers. So, x can be any value.
B. The y-intercept is (0,1). This statement is false. The y-intercept occurs when x=0, and substituting into the function gives y = 9/10^0 = 9/1 = 9.
C. It is always decreasing. This statement is false. The function I(x) = 9/10^x is actually always decreasing as x increases.
D. The y-intercept is (0,3). This statement is false, as explained in statement B.