• Q1 (a) • Q1 (b) • Q1 (c) • Q1 (d) • Q2 (a) • Q2 (b) • Q2 (c) • Q3 (a) • Q3 (b) • Q3 (c) • Q4 (a) • Q4 (b) • Q4 (c) • Q5 • Q6 • Q7 • Q8 (a) • Q8 (b) • Q8 (c) • Q8 (d) • Q9 • Q10 (a) • Q10 (b) • Q11 •
Question 08 (c) 

FullSolution Problem. Justify your answer and show your work. Full simplification of numerical answers is required unless explicitly stated otherwise. Let . Determine the intervals where is concave up, and the intervals where is concave down. 
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Hint 

What is the sign of when is concave up? When is concave down? 
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Solution  

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Please rate my easiness! It's quick and helps everyone guide their studies. Where , is concave up; where , is concave down. From part (a), we know that
Note that is never equal to zero on the interval . However, is undefined at , so does not exist at . Therefore, we note that may change sign at and . We can construct a sign table to organize our calculations: From this table we observe that is concave up on and concave down on . 