Express as a function of a DIFFERENT angle, 0^(@) <= theta < 360^(@). cos(123^(@)) cos(◻^(@))

Understand reference angles: Understand the concept of reference angles. A reference angle is the acute angle formed by the terminal side of an angle and the x-axis. It is always between 0° and 90° and is useful for finding the trigonometric function of an angle in any quadrant by relating it to an angle in the first quadrant.Determine quadrant of angle: Determine the quadrant in which the angle 123° lies. Since 123° is greater than 90° but less than 180°, it lies in the second quadrant.Find reference angle: Find the reference angle for 123°. The reference angle is found by subtracting the angle from 180° because it is in the second quadrant. Reference angle = 180° - 123° = 57°Use reference angle for cos: Use the reference angle to express cos(123°) as a function of a different angle. In the second quadrant, the cosine function is negative, and the reference angle is 57°. Therefore, cos(123°) is equal to the negative cosine of its reference angle. cos(123°) = -cos(57°)

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Express as a function of a DIFFERENT angle,
0^(@) <= theta < 360^(@).

cos(123^(@))

cos(◻^(@))

Express as a function of a DIFFERENT angle, 0^{\circ} \leq \theta<360^{\circ} . $\newline$ $\cos \left(123^{\circ}\right)$ $\newline$ $\cos \left(\square^{\circ}\right)$

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Algebra 2

Sin, cos, and tan of special angles

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Q. Express as a function of a DIFFERENT angle,

0^{\circ} \leq \theta<360^{\circ}

\newline

\cos \left(123^{\circ}\right)

\newline

\cos \left(\square^{\circ}\right)

Understand reference angles: Understand the concept of reference angles. A reference angle is the acute angle formed by the terminal side of an angle and the x-axis. It is always between $0^\circ$ and $90^\circ$ and is useful for finding the trigonometric function of an angle in any quadrant by relating it to an angle in the first quadrant.
Determine quadrant of angle: Determine the quadrant in which the angle $123°$ lies. $\newline$ Since $123°$ is greater than $90°$ but less than $180°$ , it lies in the second quadrant.
Find reference angle: Find the reference angle for $123°$ . $\newline$ The reference angle is found by subtracting the angle from $180°$ because it is in the second quadrant. $\newline$ Reference angle = $180° - 123° = 57°$
Use reference angle for cos: Use the reference angle to express $\cos(123°)$ as a function of a different angle. $\newline$ In the second quadrant, the cosine function is negative, and the reference angle is $57°$ . Therefore, $\cos(123°)$ is equal to the negative cosine of its reference angle. $\newline$ $\cos(123°) = -\cos(57°)$