<p>Need help answering this question ...</p>
<p>The distance, in feet, that a certain object travels after t seconds is given by the function d(t)=at + 1/2 bt^2, where a and b are positive constants. Which of the following fundtions, s, represents the average (arithmetic mean) rate, in feet persecond, when the object has traveled t seconds?</p>
<p>(A) s(t) = 2t
(B) s(t) = t+t^2
(C) s(t) = t^2+t^3
(D) s(t) = 1+t
(E) s(t) = 1 +t^2</p>
<p>Serene,</p>
<p>Is this an SAT question or not? And if so, what level is it? Also, Do you have the answer to this question? There seems to be a few flaws in this question if I am not erroneous.</p>
<p>Wait, since the function is defined as d(t)= at+1/2 bt^2, so in t second, the object travels at+1/2 bt^2. Henceforth, the average rate is always equals d(t) / t</p>
<p>Am I wrong?</p>
<p>You are right benjamin. The answer should be a + 1/2 bt. </p>
<p>Since this is not an answer choice, then either</p>
<p>(1) The question should have given enough information to find a and b, or
(2) The question should have asked “which of the following COULD represent the average…” But in this second case, both (A) and (D) would be solutions.</p>
<p>In summary, this is an awful question, certainly not an SAT question.</p>