Solve \(\sin\theta=\frac{\sqrt2}{2}\) for the principal value \(\theta=\arcsin\left(\frac{\sqrt2}{2}\right)\).
Question 8
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Evaluate \(\arcsin(\sin(\frac{5\pi}{6}))\).
Question 9
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Find \(\cos(\arcsin x)\) for \(-1\le x\le1\).
Question 10
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Find \(\tan(\arcsin x)\) for \(-1<x<1\).
Question 11
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Explain why \(\arcsin(2)\) is not a real number.
Question 12
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Show that \(\arcsin x+\arccos x=\frac\pi2\) for \(-1\le x\le1\).
Question 13
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Find the angle \(\theta\) in \((-\frac\pi2,\frac\pi2)\) whose tangent is \(-\sqrt3\).
Question 14
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Find \(\arctan\left(\frac{y}{x}\right)\) for \(x=3\), \(y=3\), and state what angle it gives.
Question 15
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Solve \(\arccos x=\frac{2\pi}{3}\).
Question 16
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Find all real \(x\) for which \(\arcsin x\) and \(\arccos x\) are both defined.
Question 17
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A student says \(\sin^{-1}x=\frac1{\sin x}\). Explain the notation error in the context of inverse trig functions.
Question 18
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Prove that \(\tan(\arctan x)=x\) for every real \(x\), and explain why the reverse \(\arctan(\tan\theta)=\theta\) needs a restriction.
Question 19
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Evaluate \(\arccos(\cos(\frac{5\pi}{3}))\) and explain the principal-value issue.
Question 20
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A vector has components \((-1,1)\). Explain why \(\arctan(y/x)\) alone does not identify its quadrant, and find the correct direction angle in \([0,2\pi)\).