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A pole 5 m high is fixed on the top of a...

A pole 5 m high is fixed on the top of a tower. The angle of elevation of the top of the pole as observed from a point A on the ground is `60^(@)` and the angle of depression of the point A from the top of the tower is `45^(@)`. Find the height of the tower.

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To solve the problem step by step, we will use trigonometric concepts related to angles of elevation and depression. ### Step 1: Understand the Problem We have a tower with a height we need to find, and on top of this tower, there is a pole that is 5 meters high. We denote the height of the tower as \( h \). The total height from the ground to the top of the pole is \( h + 5 \). ### Step 2: Set Up the Diagram 1. Let point \( A \) be the point on the ground from where the angles are measured. 2. Let point \( B \) be the top of the tower. 3. Let point \( C \) be the top of the pole. 4. The height of the tower is \( h \), and the height of the pole is 5 m. ### Step 3: Use the Angle of Elevation From point \( A \), the angle of elevation to point \( C \) (the top of the pole) is \( 60^\circ \). We can use the tangent function: \[ \tan(60^\circ) = \frac{\text{Opposite}}{\text{Adjacent}} = \frac{h + 5}{d} \] where \( d \) is the horizontal distance from point \( A \) to the base of the tower. Since \( \tan(60^\circ) = \sqrt{3} \), we have: \[ \sqrt{3} = \frac{h + 5}{d} \quad \text{(Equation 1)} \] ### Step 4: Use the Angle of Depression From point \( B \) (the top of the tower), the angle of depression to point \( A \) is \( 45^\circ \). Using the tangent function again: \[ \tan(45^\circ) = \frac{\text{Opposite}}{\text{Adjacent}} = \frac{h}{d} \] Since \( \tan(45^\circ) = 1 \), we have: \[ 1 = \frac{h}{d} \quad \text{(Equation 2)} \] This implies: \[ d = h \quad \text{(Equation 3)} \] ### Step 5: Substitute Equation 3 into Equation 1 Now, we substitute \( d \) from Equation 3 into Equation 1: \[ \sqrt{3} = \frac{h + 5}{h} \] ### Step 6: Solve for \( h \) Cross-multiplying gives: \[ \sqrt{3}h = h + 5 \] Rearranging the equation: \[ \sqrt{3}h - h = 5 \] Factoring out \( h \): \[ h(\sqrt{3} - 1) = 5 \] Thus, we can solve for \( h \): \[ h = \frac{5}{\sqrt{3} - 1} \] ### Step 7: Rationalize the Denominator To rationalize the denominator: \[ h = \frac{5(\sqrt{3} + 1)}{(\sqrt{3} - 1)(\sqrt{3} + 1)} = \frac{5(\sqrt{3} + 1)}{3 - 1} = \frac{5(\sqrt{3} + 1)}{2} \] ### Final Answer The height of the tower is: \[ h = \frac{5(\sqrt{3} + 1)}{2} \text{ meters} \]
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