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In `DeltaABC,angleC=90^(@)andtanA=(1)/(sqrt(3))`,find the value of sin A cosB+cosAsinB.

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To solve the problem, we will follow these steps: ### Step 1: Understand the given information We have a right triangle \( \Delta ABC \) with \( \angle C = 90^\circ \) and \( \tan A = \frac{1}{\sqrt{3}} \). We need to find the value of \( \sin A \cos B + \cos A \sin B \). ### Step 2: Draw the triangle Let's label the triangle: - \( C \) is the right angle. - Let \( A \) be one of the angles, and \( B \) be the other angle. ### Step 3: Use the tangent value to find the sides Given \( \tan A = \frac{1}{\sqrt{3}} \), we can interpret this as: \[ \tan A = \frac{\text{opposite}}{\text{adjacent}} = \frac{1}{\sqrt{3}} \] Let the opposite side (to angle \( A \)) be \( 1 \) and the adjacent side be \( \sqrt{3} \). ### Step 4: Find the hypotenuse Using the Pythagorean theorem: \[ \text{hypotenuse} = \sqrt{(\text{opposite})^2 + (\text{adjacent})^2} = \sqrt{1^2 + (\sqrt{3})^2} = \sqrt{1 + 3} = \sqrt{4} = 2 \] ### Step 5: Find \( \sin A \) and \( \cos A \) Now we can find \( \sin A \) and \( \cos A \): \[ \sin A = \frac{\text{opposite}}{\text{hypotenuse}} = \frac{1}{2} \] \[ \cos A = \frac{\text{adjacent}}{\text{hypotenuse}} = \frac{\sqrt{3}}{2} \] ### Step 6: Find \( \sin B \) and \( \cos B \) Since \( A + B = 90^\circ \), we have: \[ \sin B = \cos A = \frac{\sqrt{3}}{2} \] \[ \cos B = \sin A = \frac{1}{2} \] ### Step 7: Substitute into the expression Now we substitute into the expression \( \sin A \cos B + \cos A \sin B \): \[ \sin A \cos B + \cos A \sin B = \left(\frac{1}{2}\right)\left(\frac{1}{2}\right) + \left(\frac{\sqrt{3}}{2}\right)\left(\frac{\sqrt{3}}{2}\right) \] \[ = \frac{1}{4} + \frac{3}{4} = \frac{4}{4} = 1 \] ### Final Answer Thus, the value of \( \sin A \cos B + \cos A \sin B \) is \( 1 \). ---
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NAGEEN PRAKASHAN ENGLISH-INTRODUCTION TO TRIGONOMETRY-Revision Exercise Short Answer Questions
  1. If 3cot A=4, check whether (1-tan^2A)/(1+tan^2A)=cos^2A-sin^2Aor not.

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  2. In DeltaABC,angleC=90^(@)andtanA=(1)/(sqrt(3)),find the value of sin A...

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  3. If "cosec"theta=2, show that (cottheta+(sintheta)/(1+costheta))=2.

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  4. If sintheta=0.8,show that 5sintheta-3tantheta=0.

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  5. If costheta=(8)/(17),verify that (3-4sin^(2)theta)/(4cos^(2)theta-3)=(...

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  6. If sintheta=(3)/(5),verify that (tantheta)/(1+tan^(2)theta)=sinthetaco...

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  7. If cottheta=(b)/(a),show that (asintheta-bcostheta)/(asintheta+bcosthe...

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  8. find the value of sin60^@cos3 0^@+sin3 0^@cos6 0^@

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  9. Verify that : sin 60^@ = 2 sin 30^@ cos 30^@

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  10. If A=30^(@),verify that cos2A=cos^(2)A-sin^(2)A.

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  11. if A= 45^o then verify sin2A=2sinAcosA , cos2A=1-sin^2A

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  12. Using the formula cos A =sqrt((1+cos2A)/(2)), find the value of cos30^...

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  13. In the adjoining figure , DeltaABC is a right - angled triangle , righ...

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  14. If sin(A-B)=1/2,""""cos(A+B)=1/2, 0o<A+Blt=90o,""""A > B , find A and ...

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  15. Find the value of sin30^(@) geometrically.

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  16. Find the value of sin60^(@) geometrically.

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  17. Prove that sqrt(sec^(2)theta + cosec^(2)theta) = tantheta + cottheta.

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  18. Prove that : sqrt((1+costheta)/(1-costheta))="cosec"theta+cottheta

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  19. sqrt((1+sintheta)/(1-sintheta))+sqrt((1-sintheta)/(1+sintheta)) is equ...

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  20. Prove that : tan^(2)theta-sin^(2)theta=tan^(2)thetasin^(2)theta

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