Q. A function g(x) increases by a factor of 2 over every unit interval in x and g(0)=1.Write a function rule for g(x).
Check g(0): Check g(0) for each function to see if it equals 1.(A) g(0)=0.980=1 (This matches g(0)=1, but we need to check if it doubles over each unit interval.)(B) g(0)=20=1 (This matches g(0)=1, and we know that powers of 2 double each time the exponent increases by 1.)(C) g(0)=1−0/2=1 (This matches g(0)=1, but does it increase by a factor of 2 over each unit interval?)(D) g(0)2 (This does not match g(0)=1, so it's not the right function.)
Check doubling: Check if the functions double over each unit interval.(A) g(1)=0.981=2⋅g(0), so it doesn't double.(B) g(1)=21=2, which is 2⋅g(0), so it doubles.(C) g(1)=1−21=21, which is not 2⋅g(0), so it doesn't double.(D) We already know (D) is incorrect because g(0)=1.
Choose correct function: Choose the function that both starts at 1 and doubles over each unit interval.The correct function is (B) g(x)=2x.