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Evaluate : 2 (tan 57^(@))/(cot 33^(@))...

Evaluate :
`2 (tan 57^(@))/(cot 33^(@))-(cot 70^(@))/(tan 20^(@))-sqrt(2)cos 45^(@)`

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AI Generated Solution

The correct Answer is:
Let's evaluate the expression step by step: Given expression: \[ 2 \left( \tan 57^\circ \right) / \left( \cot 33^\circ \right) - \left( \cot 70^\circ \right) / \left( \tan 20^\circ \right) - \sqrt{2} \cos 45^\circ \] ### Step 1: Rewrite the trigonometric functions using complementary angles We know that: \[ \cot(90^\circ - \theta) = \tan(\theta) \] Using this property: - For \( \tan 57^\circ \), we can write: \[ \tan 57^\circ = \cot(90^\circ - 57^\circ) = \cot 33^\circ \] - For \( \tan 20^\circ \), we can write: \[ \tan 20^\circ = \cot(90^\circ - 20^\circ) = \cot 70^\circ \] Now, substituting these into the expression: \[ 2 \left( \cot 33^\circ \right) / \left( \cot 33^\circ \right) - \left( \cot 70^\circ \right) / \left( \cot 70^\circ \right) - \sqrt{2} \cos 45^\circ \] ### Step 2: Simplify the expression Now, simplifying the fractions: \[ 2 \cdot 1 - 1 - \sqrt{2} \cos 45^\circ \] ### Step 3: Evaluate \( \cos 45^\circ \) We know that: \[ \cos 45^\circ = \frac{1}{\sqrt{2}} \] Substituting this value into the expression: \[ 2 - 1 - \sqrt{2} \cdot \frac{1}{\sqrt{2}} \] ### Step 4: Simplify further The term \( \sqrt{2} \cdot \frac{1}{\sqrt{2}} \) simplifies to 1: \[ 2 - 1 - 1 \] ### Step 5: Final calculation Now, calculate: \[ 2 - 1 - 1 = 0 \] Thus, the final answer is: \[ \boxed{0} \] ---
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