5. Inverse Trigonometric Functions and Basic Trigonometric Equations

Inverse Sine, Cosine, & Tangent

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Multiple Choice

Evaluate the expression using a calculator. Express your answer in radians, rounding to two decimal places.
$\cos^{-1}\left(\frac14\right)$

75.52

1.82

1.32

0.97

Verified step by step guidance

Understand that $ \cos^{-1}(x) $ is the inverse cosine function, which gives the angle whose cosine is $ x $.

Identify the value for which you need to find the inverse cosine: $ x = \frac{1}{4} $.

Use a calculator to find $ \cos^{-1}\left(\frac{1}{4}\right) $. Ensure your calculator is set to radians mode.

Enter $ \frac{1}{4} $ into the calculator and apply the inverse cosine function to find the angle in radians.

Round the result to two decimal places to get the final answer.

Master Inverse Cosine with a bite sized video explanation from Patrick

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Expert video explanations

Evaluate the expression using a calculator. Express your answer in radians, rounding to two decimal places. cos−1(14)\cos^{-1}\left(\frac14\right)cos−1(41)