Answer:
I = ∫₀¹ eˣ dx
I = ∫₀¹ e⁻ˣ dx
Explanation:
Trapezoidal rule will be an overestimate if the function is concave up.
We can determine this by looking at the graph, or by evaluating the second derivative. If the second derivative is positive on the interval, the function is concave up.
f(x) = eˣ
f'(x) = eˣ
f"(x) = eˣ
On the interval [0, 1], f(x) is concave up.
f(x) = e⁻ˣ
f'(x) = -e⁻ˣ
f"(x) = e⁻ˣ
On the interval [0, 1], f(x) is concave up.
f(x) = √x = x^½
f'(x) = ½ x^(-½)
f"(x) = -¼ x^(-³/₂)
On the interval [0, 1], f(x) is concave down.
f(x) = sin x
f'(x) = cos x
f"(x) = -sin x
On the interval [0, 1], f(x) is concave down.