If cosec A = 2 then obtain the value of cot A + (sin A /1+ cos A)
Solution:
Trigonometry helps us to understand the relation between the sides and angles of a right-angle triangle. Cosec, Sec and Cot are three of the six trigonometric ratios of a right-angled triangle. Let's look into the steps below.
Given: cosec A = 2
We know that,
cosec A=1 / sinA
⇒ sin A = 1/2.......................(i)
Using trigonometric identity, we know that
sin²A + cos²A = 1..................(ii)
Now, put the value of sin A from equation (i) in equation (ii),
⇒ (1/2)² + cos²A = 1
⇒ 1/4 + cos²A = 1
⇒ 1 – 1/4 = cos²A
⇒ cos²A = 3/4
⇒ cos A = √3 / 2 ..................... (iii)
From trigonometric ratios we know that,
tan A = sin A / cos A ....................(iv)
Substituting the values of sin A from equation (i) and the value of cosA from equation (iii) in equation (iv) we get,
⇒ tan A = (1/2) × 2/√(3)
⇒ tan A = 1/√(3)
⇒ cot A = √(3) [ Since, cot A = 1/ tan A]................(v)
Now, let's evaluate
cot A + {sin A / (1+cosA)}
Substituting the values from (i), (iii) and (v) in (cot A + sinA) / (1+cosA) we get,
= √3 + {(1/2) / ( 1 + (√3/2))}
= √3 + {1 / (2 + √3)}
On evaluating,
= (2√3 + 4) / (2 + √3)
Rationalizing the denominator,
= (2√3 + 4) (2 - √3) / (2 + √3) (2 - √3)
= (4√3 + 8 - 4√3 - 6) / (4 - 3)
= 2
Thus, If cosec A = 2 then, the value of cot A + (sin A /1+ cos A) is 2
If cosec A = 2 then obtain the value of cot A + (sin A /1+ cos A)
Summary:
If cosec A = 2 then, the value of cot A + (sin A /1+ cos A) is 2
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