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PT, a tower of height 2^(x) metre, p bei...

PT, a tower of height `2^(x)` metre, p being the foot, T being the top of the tower. A, B are points on the same line with P. If `AP=2^(x+1)`m, BP=192` m and if the angle of elevation of the tower as seen from b is double the angle of the elevation of the tower as seen from A, then what is the value of x?

A

6

B

7

C

8

D

9

Text Solution

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The correct Answer is:
To solve the problem step by step, we will use the information provided in the question and apply trigonometric principles. ### Step 1: Understand the Problem We have a tower PT of height \(2^x\) meters. Points A and B are at distances \(AP = 2^{(x+1)}\) meters and \(BP = 192\) meters respectively. The angle of elevation from B is double that from A. ### Step 2: Set Up the Trigonometric Relationships From point A: - The angle of elevation is \(\theta\). - Using the tangent function, we have: \[ \tan(\theta) = \frac{PT}{AP} = \frac{2^x}{2^{(x+1)}} = \frac{2^x}{2 \cdot 2^x} = \frac{1}{2} \] From point B: - The angle of elevation is \(2\theta\). - Using the tangent function, we have: \[ \tan(2\theta) = \frac{PT}{BP} = \frac{2^x}{192} \] ### Step 3: Use the Double Angle Formula for Tangent The double angle formula for tangent is: \[ \tan(2\theta) = \frac{2\tan(\theta)}{1 - \tan^2(\theta)} \] Substituting \(\tan(\theta) = \frac{1}{2}\): \[ \tan(2\theta) = \frac{2 \cdot \frac{1}{2}}{1 - \left(\frac{1}{2}\right)^2} = \frac{1}{1 - \frac{1}{4}} = \frac{1}{\frac{3}{4}} = \frac{4}{3} \] ### Step 4: Set Up the Equation Now we equate the two expressions for \(\tan(2\theta)\): \[ \frac{2^x}{192} = \frac{4}{3} \] ### Step 5: Cross Multiply to Solve for \(2^x\) Cross multiplying gives: \[ 3 \cdot 2^x = 4 \cdot 192 \] Calculating \(4 \cdot 192\): \[ 4 \cdot 192 = 768 \] So we have: \[ 3 \cdot 2^x = 768 \] ### Step 6: Divide by 3 Dividing both sides by 3: \[ 2^x = \frac{768}{3} = 256 \] ### Step 7: Solve for \(x\) Since \(256 = 2^8\), we can equate: \[ 2^x = 2^8 \implies x = 8 \] ### Final Answer The value of \(x\) is \(8\). ---

To solve the problem step by step, we will use the information provided in the question and apply trigonometric principles. ### Step 1: Understand the Problem We have a tower PT of height \(2^x\) meters. Points A and B are at distances \(AP = 2^{(x+1)}\) meters and \(BP = 192\) meters respectively. The angle of elevation from B is double that from A. ### Step 2: Set Up the Trigonometric Relationships From point A: - The angle of elevation is \(\theta\). ...
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