Answer
Here are the simplified expressions:
1. **2.1:** \(\frac{\sin(x)}{-\sin^2(x) + \cos^2(x)}\)
2. **2.3:** \(-1\)
3. **2.4:** \(\frac{\sin^2 \theta}{-\sin^2 \theta + 1}\)
4. **2.5:** \(\frac{\sin(104^{\circ}) \cdot (2 \cos^2(15^{\circ}))}{\tan(38^{\circ}) \cdot \sin^2(52^{\circ})}\)
5. **2.6:** \(\frac{\cos(\theta) - \cos(\theta) \sin(\theta)}{-\tan(100^{\circ})}\)
Solution
Simplify the expression by following steps:
- step0: Solution:
\(\frac{2.6\left(\sin\left(90+\theta \right)+\cos\left(180+\theta \right)\sin\left(-\theta \right)\right)}{\left(\sin\left(180\right)-\tan\left(100\right)\right)}\)
- step1: Remove the parentheses:
\(\frac{2.6\left(\sin\left(90+\theta \right)+\cos\left(180+\theta \right)\sin\left(-\theta \right)\right)}{\sin\left(180\right)-\tan\left(100\right)}\)
- step2: Rewrite the expression:
\(\frac{2.6\left(\sin\left(90+\theta \right)+\cos\left(\theta +180\right)\sin\left(-\theta \right)\right)}{\sin\left(180\right)-\tan\left(100\right)}\)
- step3: Transform the expression:
\(\frac{2.6\left(\sin\left(90+\theta \right)+\cos\left(\theta +180\right)\left(-\sin\left(\theta \right)\right)\right)}{\sin\left(180\right)-\tan\left(100\right)}\)
- step4: Rewrite the expression:
\(\frac{2.6\left(\sin\left(\theta +90\right)+\cos\left(\theta +180\right)\left(-\sin\left(\theta \right)\right)\right)}{\sin\left(180\right)-\tan\left(100\right)}\)
- step5: Rewrite the expression:
\(\frac{2.6\left(\sin\left(\theta +90\right)-\cos\left(\theta +180\right)\sin\left(\theta \right)\right)}{\sin\left(180\right)-\tan\left(100\right)}\)
- step6: Multiply the terms:
\(\frac{2.6\sin\left(\theta +90\right)-2.6\cos\left(\theta +180\right)\sin\left(\theta \right)}{\sin\left(180\right)-\tan\left(100\right)}\)
- step7: Convert the expressions:
\(\frac{\frac{13}{5}\sin\left(\theta +90\right)-\frac{13}{5}\cos\left(\theta +180\right)\sin\left(\theta \right)}{\sin\left(180\right)-\tan\left(100\right)}\)
- step8: Simplify the expression:
\(\frac{13\sin\left(\theta +90\right)-13\cos\left(\theta +180\right)\sin\left(\theta \right)}{5\sin\left(180\right)-5\tan\left(100\right)}\)
- step9: Rewrite the expression:
\(\left(13\sin\left(\theta +90\right)-13\cos\left(\theta +180\right)\sin\left(\theta \right)\right)\left(5\sin\left(180\right)-5\tan\left(100\right)\right)^{-1}\)
- step10: Calculate:
\(\left(13\sin\left(\theta +90\right)-13\cos\left(\theta +180\right)\sin\left(\theta \right)\right)\times \frac{1}{5\sin\left(180\right)-5\tan\left(100\right)}\)
- step11: Calculate:
\(\frac{13}{5\sin\left(180\right)-5\tan\left(100\right)}\times \sin\left(\theta +90\right)+\frac{13}{5\tan\left(100\right)-5\sin\left(180\right)}\times \cos\left(\theta +180\right)\sin\left(\theta \right)\)
- step12: Rewrite the expression:
\(\frac{13}{5\sin\left(180\right)-5\tan\left(100\right)}\times \sin\left(\theta +90\right)+\frac{13}{-5\sin\left(180\right)+5\tan\left(100\right)}\times \sin\left(\theta \right)\cos\left(\theta +180\right)\)
- step13: Simplify:
\(\frac{13\sin\left(\theta +90\right)-13\sin\left(\theta \right)\cos\left(\theta +180\right)}{5\sin\left(180\right)-5\tan\left(100\right)}\)
Calculate or simplify the expression \( 2.5 * (\sin(104) * (2 * \cos^2(15))) / (\tan(38) * \sin^2(412)) \).
Calculate the value by following steps:
- step0: Calculate:
\(\frac{2.5\left(\sin\left(104\right)\left(2\cos^{2}\left(15\right)\right)\right)}{\left(\tan\left(38\right)\sin^{2}\left(412\right)\right)}\)
- step1: Remove the parentheses:
\(\frac{2.5\sin\left(104\right)\times 2\cos^{2}\left(15\right)}{\tan\left(38\right)\sin^{2}\left(412\right)}\)
- step2: Multiply the terms:
\(\frac{5\sin\left(104\right)\cos^{2}\left(15\right)}{\tan\left(38\right)\sin^{2}\left(412\right)}\)
- step3: Calculate the trigonometric value:
\(-15.719411\)
Let's simplify each expression step by step without using a calculator.
### 2.1
\[
\frac{\tan(180^{\circ}+x) \cdot \cos(360^{\circ}-x)}{\sin(180-x) \cdot \cos(90^{\circ}+x) + \cos(540^{\circ}+x) \cdot \cos(-x)}
\]
**Step 1: Simplify the trigonometric functions.**
- \(\tan(180^{\circ}+x) = \tan(x)\)
- \(\cos(360^{\circ}-x) = \cos(x)\)
- \(\sin(180-x) = \sin(x)\)
- \(\cos(90^{\circ}+x) = -\sin(x)\)
- \(\cos(540^{\circ}+x) = \cos(x)\)
- \(\cos(-x) = \cos(x)\)
**Step 2: Substitute these values into the expression.**
\[
\frac{\tan(x) \cdot \cos(x)}{\sin(x) \cdot (-\sin(x)) + \cos(x) \cdot \cos(x)}
\]
This simplifies to:
\[
\frac{\tan(x) \cdot \cos(x)}{-\sin^2(x) + \cos^2(x)}
\]
**Step 3: Use the identity \(\tan(x) = \frac{\sin(x)}{\cos(x)}\)**
\[
\frac{\frac{\sin(x)}{\cos(x)} \cdot \cos(x)}{-\sin^2(x) + \cos^2(x)} = \frac{\sin(x)}{-\sin^2(x) + \cos^2(x)}
\]
### 2.3
\[
\sin(90^{\circ}-x) \cdot \cos(180^{\circ}-x) + \tan(x) \cdot \cos(-x) \cdot \sin(180^{\circ}+x)
\]
**Step 1: Simplify the trigonometric functions.**
- \(\sin(90^{\circ}-x) = \cos(x)\)
- \(\cos(180^{\circ}-x) = -\cos(x)\)
- \(\tan(x) = \frac{\sin(x)}{\cos(x)}\)
- \(\cos(-x) = \cos(x)\)
- \(\sin(180^{\circ}+x) = -\sin(x)\)
**Step 2: Substitute these values into the expression.**
\[
\cos(x) \cdot (-\cos(x)) + \frac{\sin(x)}{\cos(x)} \cdot \cos(x) \cdot (-\sin(x))
\]
This simplifies to:
\[
-\cos^2(x) - \sin^2(x) = -1
\]
### 2.4
\[
\frac{\sin^2 \theta}{\sin(180^{\circ}-\theta) \cdot \cos(90^{\circ}+\theta) + \tan 45^{\circ}}
\]
**Step 1: Simplify the trigonometric functions.**
- \(\sin(180^{\circ}-\theta) = \sin(\theta)\)
- \(\cos(90^{\circ}+\theta) = -\sin(\theta)\)
- \(\tan(45^{\circ}) = 1\)
**Step 2: Substitute these values into the expression.**
\[
\frac{\sin^2 \theta}{\sin(\theta) \cdot (-\sin(\theta)) + 1} = \frac{\sin^2 \theta}{-\sin^2 \theta + 1}
\]
### 2.5
\[
\frac{\sin(104^{\circ}) \cdot (2 \cos^2(15^{\circ}))}{\tan(38^{\circ}) \cdot \sin^2(412^{\circ})}
\]
**Step 1: Simplify the trigonometric functions.**
- \(\sin(412^{\circ}) = \sin(52^{\circ})\) (since \(412 - 360 = 52\))
**Step 2: Substitute these values into the expression.**
\[
\frac{\sin(104^{\circ}) \cdot (2 \cos^2(15^{\circ}))}{\tan(38^{\circ}) \cdot \sin^2(52^{\circ})}
\]
### 2.6
\[
\frac{\sin(90^{\circ}+\theta) + \cos(180^{\circ}+\theta) \sin(-\theta)}{\sin(180^{\circ}) - \tan(100^{\circ})}
\]
**Step 1: Simplify the trigonometric functions.**
- \(\sin(90^{\circ}+\theta) = \cos(\theta)\)
- \(\cos(180^{\circ}+\theta) = -\cos(\theta)\)
- \(\sin(-\theta) = -\sin(\theta)\)
- \(\sin(180^{\circ}) = 0\)
**Step 2: Substitute these values into the expression.**
\[
\frac{\cos(\theta) - \cos(\theta) \sin(\theta)}{0 - \tan(100^{\circ})}
\]
### Summary of Results
- **2.1:** \(\frac{\sin(x)}{-\sin^2(x) + \cos^2(x)}\)
- **2.3:** \(-1\)
- **2.4:** \(\frac{\sin^2 \theta}{-\sin^2 \theta + 1}\)
- **2.5:** \(\frac{\sin(104^{\circ}) \cdot (2 \cos^2(15^{\circ}))}{\tan(38^{\circ}) \cdot \sin^2(52^{\circ})}\)
- **2.6:** \(\frac{\cos(\theta) - \cos(\theta) \sin(\theta)}{-\tan(100^{\circ})}\)
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