Trig Expression Functions
1. **Evaluate the expression:** $$8 \sin 45^\circ - \sin 60^\circ \cdot \cos 30^\circ - \frac{1}{4} \tan 45^\circ$$
2. **Recall exact trigonometric values:**
- $\sin 45^\circ = \frac{\sqrt{2}}{2}$
- $\sin 60^\circ = \frac{\sqrt{3}}{2}$
- $\cos 30^\circ = \frac{\sqrt{3}}{2}$
- $\tan 45^\circ = 1$
3. **Substitute values:**
$$8 \times \frac{\sqrt{2}}{2} - \frac{\sqrt{3}}{2} \times \frac{\sqrt{3}}{2} - \frac{1}{4} \times 1$$
4. **Simplify each term:**
- $8 \times \frac{\sqrt{2}}{2} = 4\sqrt{2}$
- $\frac{\sqrt{3}}{2} \times \frac{\sqrt{3}}{2} = \frac{3}{4}$
- $\frac{1}{4} \times 1 = \frac{1}{4}$
5. **Rewrite expression:**
$$4\sqrt{2} - \frac{3}{4} - \frac{1}{4}$$
6. **Combine fractions:**
$$4\sqrt{2} - \frac{3+1}{4} = 4\sqrt{2} - 1$$
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7. **For $f(x) = \sin x - 1$ and $g(x) = 2 \tan x$:**
**3.6.1 Period of $g(x)$:**
- The period of $\tan x$ is $180^\circ$.
- Scaling by 2 does not change the period.
- So, period of $g(x) = 180^\circ$.
**3.6.2 Amplitude of $f(x)$:**
- $\sin x$ has amplitude 1.
- Vertical shift down by 1 does not change amplitude.
- So, amplitude of $f(x)$ is 1.
**3.6.3 Range of $g(x)$:**
- $\tan x$ ranges over all real numbers.
- Scaling by 2 stretches range but still all real numbers.
- So, range of $g(x)$ is $(-\infty, \infty)$.
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**3.6.4 Sketch details for $x \in [0^\circ, 360^\circ]$:**
- $f(x) = \sin x - 1$ oscillates between $-2$ and $0$.
- Intercepts of $f(x)$ with x-axis where $\sin x = 1$ at $x=90^\circ$.
- Turning points of $f(x)$ at $x=270^\circ$ (minimum at $-2$) and $x=90^\circ$ (maximum at $0$).
- $g(x) = 2 \tan x$ has vertical asymptotes at $x=90^\circ$ and $x=270^\circ$.
- Intercepts of $g(x)$ at $x=0^\circ, 180^\circ, 360^\circ$.
- $g(45^\circ) = 2 \times 1 = 2$.
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**Final answers:**
- Expression value: $$4\sqrt{2} - 1$$
- Period of $g(x)$: $$180^\circ$$
- Amplitude of $f(x)$: $$1$$
- Range of $g(x)$: $$(-\infty, \infty)$$