A poll commissioned by a politician estimates that t days after he makes a statement degenerating 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 degenerating 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 day is 10 days after he made the statement.

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

2. When was his support at its lowest level?

3. What was his minimum support level?