
Brian H. answered 01/08/21
Multi-Subject Tutor for High School Students and Above
•The degree of f is odd TRUE
The highest exponent on the variable is 5, which is odd, so the function is odd. This means that the function values tend towards opposite signs of ♾ as x goes to opposite signs of ♾.
•f(x) approaches ♾ as x approaches -♾ TRUE
An odd function which has a negative leading coefficient (the coefficient on the highest power of the variable, -1 in this case, on x5) approaches +♾ as x approaches -♾, and the function approaches -♾ as x approaches +♾.
•f has a zero at x=1 TRUE
If f has a zero at this value of x, the function will evaluate to be zero when x is 1. Simply substitute, and evaluate:
f(1) = 6(1)2 - (1)5 - 8 + 3(1)3 = 6 - 1 - 8 + 3 = 0
•The leading coefficient of f is positive FALSE
We already determined the leading coefficient (-1), and it is not positive.
•f(x) approaches -♾ as x approaches ♾ TRUE
See the explanation above, in the second option.
•f has a zero at x=2 FALSE
See the explanation above, in the third option. At x=2, the function evaluates to:
f(2) = 6(2)2 - (2)5 - 8 + 3(2)3 = 6*4 - 32 - 8 + 3*8 = 24 - 32 - 8 + 24 = 48 - 40 = 8 ≠ 0