Skip to main content
Ch. 5 - Integration
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Non è quello che usi tu?Cambia libro di testo
Capitolo 5, Problema 5.5.90

Integrals with sin² 𝓍 and cos² 𝓍 Evaluate the following integrals.                                                                                                             
                                                                                                                                                                    
 ∫₀^π/⁴ cos² 8θ dθ

Guida verificata passo dopo passo
1
Step 1: Recognize that the integral involves cos²(8θ). To simplify this, use the trigonometric identity cos²(x) = (1 + cos(2x)) / 2.
Step 2: Substitute the identity into the integral. The integral becomes ∫₀^(π/4) [(1 + cos(16θ)) / 2] dθ.
Step 3: Split the integral into two separate integrals: (1/2) ∫₀^(π/4) 1 dθ + (1/2) ∫₀^(π/4) cos(16θ) dθ.
Step 4: Evaluate the first integral, (1/2) ∫₀^(π/4) 1 dθ, which is straightforward as it represents the area under a constant function. For the second integral, (1/2) ∫₀^(π/4) cos(16θ) dθ, use the formula for the integral of cos(kx), which is (1/k) sin(kx).
Step 5: Apply the limits of integration (0 to π/4) to both parts of the integral. For the first part, calculate the result of (1/2) θ evaluated at the limits. For the second part, calculate (1/2) * (1/16) * sin(16θ) evaluated at the limits.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
3m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Trigonometric Identities

Trigonometric identities are equations involving trigonometric functions that are true for all values of the variables. Key identities include the Pythagorean identities, such as sin²(x) + cos²(x) = 1, and double angle formulas. These identities are essential for simplifying integrals involving sin²(x) and cos²(x), allowing for easier evaluation.
Video consigliato:
7:17
Verifying Trig Equations as Identities

Integration Techniques

Integration techniques are methods used to find the integral of a function. Common techniques include substitution, integration by parts, and using trigonometric identities to simplify the integrand. For integrals involving cos²(θ), applying the identity cos²(θ) = (1 + cos(2θ))/2 can transform the integral into a more manageable form.
Video consigliato:
Percorso guidato
06:18
Integration by Parts for Definite Integrals

Definite Integrals

Definite integrals calculate the area under a curve between two specified limits. The notation ∫ₐᵇ f(x) dx represents the integral of f(x) from a to b. Evaluating definite integrals often involves finding the antiderivative of the function and applying the Fundamental Theorem of Calculus, which states that the definite integral can be computed by evaluating the antiderivative at the upper and lower limits.
Video consigliato:
Percorso guidato
05:43
Definition of the Definite Integral
Pratica correlata
Domanda del libro di testo

Max/min of area functions Suppose ƒ is continuous on [0 ,∞) and A(𝓍) is the net area of the region bounded by the graph of ƒ and the t-axis on [0, x]. Show that the local maxima and minima of A occur at the zeros of ƒ. Verify this fact with the function ƒ(𝓍) = 𝓍² - 10𝓍.

46
views
Domanda del libro di testo

{Use of Tech} Sigma notation for Riemann sums Use sigma notation to write the following Riemann sums. Then evaluate each Riemann sum using Theorem 5.1 or a calculator.

The right Riemann sum for ƒ(𝓍)) = x + 1 on [0, 4] with n = 50.

95
views
Domanda del libro di testo

Definite integrals Use geometry (not Riemann sums) to evaluate the following definite integrals. Sketch a graph of the integrand, show the region in question, and interpret your result.                                                                                                                                      

                                                                                                                                                                                       

 ∫₀⁴ (8―2𝓍) d𝓍

86
views
Domanda del libro di testo

Definite integrals from graphs The figure shows the areas of regions bounded by the graph of ƒ and the 𝓍-axis. Evaluate the following integrals.



∫₀ᵃ ƒ(𝓍) d𝓍

57
views
Domanda del libro di testo

Average values Find the average value of the following functions on the given interval. Draw a graph of the function and indicate the average value.

ƒ(𝓍) = 1/(𝓍² + 1) on [―1, 1]

83
views
Domanda del libro di testo

Areas of regions Find the area of the following regions.                                                                                                                   

                                                                                                                                                                 The region bounded by the graph of ƒ(𝓍) = (𝓍―4)⁴ and the 𝓍-axis between and 𝓍 = 2 and 𝓍= 6

63
views