5 In this question, you are required to investigate the curve with equation
$$y = x ^ { m } ( 1 - x ) ^ { n } , \quad 0 \leqslant x \leqslant 1 ,$$
for various positive values of \(m\) and \(n\).
- On separate diagrams, sketch the curve in each of the following cases.
(A) \(m = 1 , n = 1\),
(B) \(m = 2 , n = 2\),
(C) \(m = 2 , n = 4\),
(D) \(m = 4 , n = 2\). - What feature does the curve have when \(m = n\) ?
What is the effect on the curve of interchanging \(m\) and \(n\) when \(m \neq n\) ?
- Describe how the \(x\)-coordinate of the maximum on the curve varies as \(m\) and \(n\) vary. Use calculus to determine the \(x\)-coordinate of the maximum.
- Find the condition on \(m\) for the gradient to be zero when \(x = 0\). State a corresponding result for the gradient to be zero when \(x = 1\).
- Use your calculator to investigate the shape of the curve for large values of \(m\) and \(n\). Hence conjecture what happens to the value of the integral \(\int _ { 0 } ^ { 1 } x ^ { m } ( 1 - x ) ^ { n } \mathrm {~d} x\) as \(m\) and \(n\) tend to infinity.
- Use your calculator to investigate the shape of the curve for small values of \(m\) and \(n\). Hence conjecture what happens to the shape of the curve as \(m\) and \(n\) tend to zero.
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