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Ch. 3 - Trigonometric Identities and Equations
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601Non è quello che usi tu?Cambia libro di testo
Capitolo 3, Problema 3.2.57c

In Exercises 57–64, find the exact value of the following under the given conditions:
c. tan (α + β)
sin α = 3/5, α lies in quadrant I, and sin β = 5/13, β lies in quadrant II.

Guida verificata passo dopo passo
1
Identify the given values: \(\sin \alpha = \frac{3}{5}\) with \(\alpha\) in quadrant I, and \(\sin \beta = \frac{5}{13}\) with \(\beta\) in quadrant II.
Use the Pythagorean identity to find \(\cos \alpha\) and \(\cos \beta\). Since \(\sin^2 \theta + \cos^2 \theta = 1\), calculate \(\cos \alpha = \sqrt{1 - \sin^2 \alpha}\) and \(\cos \beta = -\sqrt{1 - \sin^2 \beta}\) (negative because \(\beta\) is in quadrant II where cosine is negative).
Calculate \(\tan \alpha\) and \(\tan \beta\) using the definitions \(\tan \theta = \frac{\sin \theta}{\cos \theta}\) with the values found in the previous step.
Apply the tangent addition formula: \(\tan(\alpha + \beta) = \frac{\tan \alpha + \tan \beta}{1 - \tan \alpha \tan \beta}\).
Substitute the values of \(\tan \alpha\) and \(\tan \beta\) into the formula and simplify the expression to find the exact value of \(\tan(\alpha + \beta)\).

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