(a)
We have been given an equation 
. Upon taking derivative of this equation with respect to x on both the sides, we get:
(b)
In order to write the equation of tangent line, we need to find the slope of the line. We know that point (3,11) lies on the graph. Therefore, we write the slope of the tangent as:
Therefore, equation of tangent line is:
(c)
We know that slope of tangent is given as 
. The tangent will be vertical when denominator of slope is zero, that is:
<h2>Major: Environmental Science</h2><h2>When coal and oil are burned, they form acids that fall to the earth as rain. Acid rain can do a lot of damage, such as killing off living things in lakes. Scientists figured out, however, that lakes on limestone rock were less affected than others. Why? Limestone weakens acid. So as a short-term solution, scientists added lime to lakes where it doesn't occur naturally.</h2>
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