A farmer has 100 m of fence for a rectangular pen against a barn wall (no fence on the wall side). What is the largest area?
Answer and explanation
Correct answer: D. 1250 square metres, with width 25 m
- Step 1: With width x, length is 100 - 2x, so A = x(100 - 2x). Step 2. The vertex is at x = 25, so A = 25(50) = 1250. Answer: 1250 square metres. Why not the others: the other values ignore the barn or are not maxima of this area function.
Practise more Trigonometry, Sequences, Calculus and Data.
Free questions with an explanation for every one, and full timed Ontario Secondary School Diploma (OSSD) mock tests.
More Trigonometry, Sequences, Calculus and Data questions
- What is the exact value of cos 60 degrees?
- In triangle ABC, A = 40 degrees, B = 70 degrees and a = 8. What is b, to one decimal?
- Two sides of a triangle are 7 and 9 with a 60 degree angle between them. How long is the third side, to one decimal?
- Convert 150 degrees to radians.
- What is the period of y = 3 sin(4x)?
- Solve 2 sin x = sqrt(3) for 0 <= x < 2pi.