Approximating Definite Integrals — Question 2

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Question 2

Use M4M_4 to approximate ∫02e−x2dx.\int_0^2e^{-x^2}\,dx. Give the exponential form and a decimal.

Original worksheet page 1: question and worked solution for 1-10-002
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Question 2 – Solution

Step 1: Find the width. h=2−04=0.5.h=\frac{2-0}{4}=0.5. Step 2: Find the four midpoints. 0.25,0.75,1.25,1.75.0.25,\qquad0.75,\qquad1.25,\qquad1.75. Step 3: Apply the midpoint formula. M4=h∑i=14f(mi)=0.5(e−(0.25)2+e−(0.75)2+e−(1.25)2+e−(1.75)2).\begin{align*} M_4&=h\sum_{i=1}^4f(m_i)\\ &=0.5\left(e^{-(0.25)^2}+e^{-(0.75)^2} +e^{-(1.25)^2}+e^{-(1.75)^2}\right). \end{align*} Step 4: Evaluate. M4≈0.88278895.M_4\approx0.88278895. M4≈0.8828\boxed{M_4\approx0.8828}

Original worksheet page 2: question and worked solution for 1-10-002

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