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If secA=cosecA" and "0^(@) le A le 90^(@...

If `secA=cosecA" and "0^(@) le A le 90^(@)`, state the value of A.

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To solve the equation \( \sec A = \csc A \) where \( 0^\circ \leq A \leq 90^\circ \), we can follow these steps: ### Step 1: Write the definitions of secant and cosecant The secant and cosecant functions are defined as: \[ \sec A = \frac{1}{\cos A} \quad \text{and} \quad \csc A = \frac{1}{\sin A} \] ### Step 2: Set the two definitions equal to each other From the given equation \( \sec A = \csc A \), we can substitute the definitions: \[ \frac{1}{\cos A} = \frac{1}{\sin A} \] ### Step 3: Cross-multiply to eliminate the fractions Cross-multiplying gives us: \[ \sin A = \cos A \] ### Step 4: Use the relationship between sine and cosine The equation \( \sin A = \cos A \) implies that the angle \( A \) must be such that the sine and cosine values are equal. This occurs at: \[ A = 45^\circ \] ### Step 5: Verify the solution Since \( 0^\circ \leq A \leq 90^\circ \), we check if \( A = 45^\circ \) satisfies the original equation: - Calculate \( \sec 45^\circ \): \[ \sec 45^\circ = \frac{1}{\cos 45^\circ} = \frac{1}{\frac{\sqrt{2}}{2}} = \sqrt{2} \] - Calculate \( \csc 45^\circ \): \[ \csc 45^\circ = \frac{1}{\sin 45^\circ} = \frac{1}{\frac{\sqrt{2}}{2}} = \sqrt{2} \] Since both values are equal, \( \sec 45^\circ = \csc 45^\circ \). ### Conclusion Thus, the value of \( A \) is: \[ \boxed{45^\circ} \]
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ICSE-TRIGONOMETRICAL RATIOS OF STANDARD ANGLES-EXERCISE 23(A)
  1. Prove that : 4(sin^(4)30^(@)+cos^(4)60^(@))-3(cos^(2)45^(@)-sin^(2)...

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  2. If sinx =cosx and x is acute, state the value of x.

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  3. If secA=cosecA" and "0^(@) le A le 90^(@), state the value of A.

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  4. If tantheta=cottheta" and "0^(@) le theta le 90^(@), state the value o...

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  5. If sinx=cosy, write the relation between x and y, if both the angles x...

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  6. If sinx=cosy, then x+y=45^(@), write true or false.

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  7. sectheta.cottheta=cosectheta, write true or false.

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  8. For any angle theta, state the value of : " "sin^(2)theta+cos...

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  9. State for any acute angle theta whether : sintheta increases or decr...

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  10. State for any acute angle theta whether : costheta increases or decr...

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  11. State for any acute angle theta whether : tantheta increases or decr...

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  12. If sqrt(3)=1*732, find (correct to two decimal places) the value of th...

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  13. Evaluate : (cos3A-3cos4A)/(sin3A+2sin4A)," when "A=15^(@).

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  14. Evaluate : (3sin3B+2cos(2B+5^(@)))/(2cos3B-sin(2B-10^(@))), when B...

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  15. Find the value of : sin30^(@)cos30^(@)

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  16. Find the value of : tan30^(@)tan60^(@)

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  17. Find the value of : cos^(2)60^(@)+sin^(2)30^(@)

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  18. Find the value of : cosec^(2)60^(@)-tan^(2)30^(@)

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  19. Find the value of : sin^(2)30^(@)+cos^(2)30^(@)+cot^(2)45^(@)

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  20. Find the value of : cos^(2)60^(@)+sec^(2)30^(@)+tan^(2)45^(@)

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