ections: evaluate the following expressions w...
ections: evaluate the following expressions without a calculator. 1. $cos^{-1}(\frac{1}{2})$ 2. $sin^{-1}(-\frac{sqrt{2}}{2})$ 3. $arctan(1)$ 4. $arccos(-\frac{sqrt{3}}{2})$ 5. $arcsin(-\frac{1}{2})$ 6. $\tan^{-1}(-\frac{sqrt{3}}{3})$ 7. $\tan^{-1}(-1)$ 8. $cos^{-1}(\frac{sqrt{3}}{2})$ 9. $arcsin(0)$ 10. $cos^{-1}(\frac{sqrt{2}}{2})$ 11. $arccos(-\frac{sqrt{3}}{2})$ 12. $arctan(sqrt{3})$
Answer
# Explanation:
## Step1: Recall inverse - cosine range
The range of \(y = \cos^{-1}(x)\) is \([0,\pi]\). We know that \(\cos(\frac{\pi}{3})=\frac{1}{2}\), so \(\cos^{-1}(\frac{1}{2})=\frac{\pi}{3}\).
## Step2: Recall inverse - sine range
The range of \(y=\sin^{-1}(x)\) is \([-\frac{\pi}{2},\frac{\pi}{2}]\). Since \(\sin(-\frac{\pi}{4}) =-\frac{\sqrt{2}}{2}\), then \(\sin^{-1}(-\frac{\sqrt{2}}{2})=-\frac{\pi}{4}\).
## Step3: Recall inverse - tangent range
The range of \(y = \tan^{-1}(x)\) is \((-\frac{\pi}{2},\frac{\pi}{2})\). As \(\tan(\frac{\pi}{4}) = 1\), so \(\arctan(1)=\frac{\pi}{4}\).
## Step4: For \(\arccos(-\frac{\sqrt{3}}{2})\)
Since the range of \(y=\cos^{-1}(x)\) is \([0,\pi]\) and \(\cos(\frac{5\pi}{6})=-\frac{\sqrt{3}}{2}\), then \(\arccos(-\frac{\sqrt{3}}{2})=\frac{5\pi}{6}\).
## Step5: For \(\arcsin(-\frac{1}{2})\)
With the range of \(y = \sin^{-1}(x)\) being \([-\frac{\pi}{2},\frac{\pi}{2}]\) and \(\sin(-\frac{\pi}{6})=-\frac{1}{2}\), we have \(\arcsin(-\frac{1}{2})=-\frac{\pi}{6}\).
## Step6: For \(\tan^{-1}(-\frac{\sqrt{3}}{3})\)
Given the range of \(y=\tan^{-1}(x)\) is \((-\frac{\pi}{2},\frac{\pi}{2})\) and \(\tan(-\frac{\pi}{6})=-\frac{\sqrt{3}}{3}\), so \(\tan^{-1}(-\frac{\sqrt{3}}{3})=-\frac{\pi}{6}\).
## Step7: For \(\tan^{-1}(-1)\)
Since the range of \(y = \tan^{-1}(x)\) is \((-\frac{\pi}{2},\frac{\pi}{2})\) and \(\tan(-\frac{\pi}{4})=-1\), then \(\tan^{-1}(-1)=-\frac{\pi}{4}\).
## Step8: For \(\cos^{-1}(\frac{\sqrt{3}}{2})\)
As the range of \(y=\cos^{-1}(x)\) is \([0,\pi]\) and \(\cos(\frac{\pi}{6})=\frac{\sqrt{3}}{2}\), we get \(\cos^{-1}(\frac{\sqrt{3}}{2})=\frac{\pi}{6}\).
## Step9: For \(\arcsin(0)\)
With the range of \(y = \sin^{-1}(x)\) being \([-\frac{\pi}{2},\frac{\pi}{2}]\) and \(\sin(0) = 0\), so \(\arcsin(0)=0\).
## Step10: For \(\cos^{-1}(\frac{\sqrt{2}}{2})\)
Since the range of \(y=\cos^{-1}(x)\) is \([0,\pi]\) and \(\cos(\frac{\pi}{4})=\frac{\sqrt{2}}{2}\), then \(\cos^{-1}(\frac{\sqrt{2}}{2})=\frac{\pi}{4}\).
## Step11: For \(\arccos(-\frac{\sqrt{3}}{2})\) (again)
The range of \(y=\cos^{-1}(x)\) is \([0,\pi]\) and \(\cos(\frac{5\pi}{6})=-\frac{\sqrt{3}}{2}\), so \(\arccos(-\frac{\sqrt{3}}{2})=\frac{5\pi}{6}\).
## Step12: For \(\arctan(\sqrt{3})\)
Given the range of \(y=\tan^{-1}(x)\) is \((-\frac{\pi}{2},\frac{\pi}{2})\) and \(\tan(\frac{\pi}{3})=\sqrt{3}\), so \(\arctan(\sqrt{3})=\frac{\pi}{3}\).
# Answer:
1. \(\frac{\pi}{3}\)
2. \(-\frac{\pi}{4}\)
3. \(\frac{\pi}{4}\)
4. \(\frac{5\pi}{6}\)
5. \(-\frac{\pi}{6}\)
6. \(-\frac{\pi}{6}\)
7. \(-\frac{\pi}{4}\)
8. \(\frac{\pi}{6}\)
9. \(0\)
10. \(\frac{\pi}{4}\)
11. \(\frac{5\pi}{6}\)
12. \(\frac{\pi}{3}\)