A poll commissioned by a politician estimates that t days after he makes a statement denigrating women, the percentage of his constituency (those who support him at the time he made the statement)...

A poll commissioned by a politician estimates that t days after he makes a statement denigrating women, the percentage of his constituency (those who support him at the time he made the statement) that still supports him is given by S(t) 75(t²-3t+25)/t²+3t+25 The election is 10 days after he made the statement.

 (i) If the derivative S’(t) may be thought of as an approval rate, derivate the a function for his approval rate.

(ii) When was his support at its lowest level?

 (iii) What was his minimum support level?