cos(x)= 15/21

Lösung

cos (x) = \frac{15}{21}

x = 0.77519 \dots + 2 πn, x = 2 π - 0.77519 \dots + 2 πn

Grad

x = 44.41530 \dots^{\circ} + 36 0^{\circ} n, x = 315.58469 \dots^{\circ} + 36 0^{\circ} n

Schritte zur Lösung

cos (x) = \frac{15}{21}

Streiche die gemeinsamen Faktoren:

3

cos (x) = \frac{5}{7}

Wende die Eigenschaften der Trigonometrie an

cos (x) = \frac{5}{7}

Allgemeine Lösung für

cos (x) = \frac{5}{7}

cos (x) = a \Rightarrow x = arccos (a) + 2 πn, x = 2 π - arccos (a) + 2 πn

x = arccos (\frac{5}{7}) + 2 πn, x = 2 π - arccos (\frac{5}{7}) + 2 πn

x = arccos (\frac{5}{7}) + 2 πn, x = 2 π - arccos (\frac{5}{7}) + 2 πn

Zeige Lösungen in Dezimalform

x = 0.77519 \dots + 2 πn, x = 2 π - 0.77519 \dots + 2 πn

cos (t) = \frac{3}{5}

3 + 4 cos (2 x) + 2 cos (4 x) = 0

cos (θ) = - \frac{4}{5}, sin (2 θ), 18 0^{\circ} < θ < 27 0^{\circ}

2 - 2 sin^{2} (3 x) = 1

4 cos^{2} (x) = 5 - 4 sin (x), 0 \leq x \leq 2 π