Apply Newton–Raphson to f(x) = e−x − x with the starting value x₀ = 0.5. Find x1.
Numerical methods worksheet with answers
1.Easy
f(x) = e−x − xf′(x) = −e−x − 1x₀ = 0.5
x1 =
2.Easy
Use the bisection method on f(x) = cos x − x with the starting interval [0, 1]. Find the midpoint c3 of step 3.
f(x) = cos x − x[a, b] = [0, 1]n = 3
c3 =
3.Medium
The trapezoid rule is used for ∫13 1/x dx. The error is at most (b − a)³·M/(12n²) with M = max|f″| on [1, 3]. Find the smallest number of strips n that guarantees an error below 1 × 10⁻⁵.
f(x) = 1/x[a, b] = [1, 3]ε = 1 × 10⁻⁵
n =
4.Medium
The trapezoid rule is used for ∫12 1/x dx. The error is at most (b − a)³·M/(12n²) with M = max|f″| on [1, 2]. Find the smallest number of strips n that guarantees an error below 0.001.
f(x) = 1/x[a, b] = [1, 2]ε = 0.001
n =
5.Hard
Use Euler's method with h = 0.2 for y′ = −2ty, y(0) = 1 to estimate y4 ≈ y(0.8).
y′ = −2tyy(0) = 1h = 0.2
y4 =
6.Hard
Use Euler's method with h = 0.1 for y′ = e−ty, y(0) = 0.5 to estimate y3 ≈ y(0.3).
y′ = e−tyy(0) = 0.5h = 0.1
y3 =
Answer key
- 1. x1 = 0.5663
- 2. c3 = 0.625
- 3. n = 366
- 4. n = 13
- 5. y4 = 0.5873
- 6. y3 = 0.7812
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