If (Cosec A - Cot A) = 2/3, then (Cosec
A + Cot A) = ?
Answers
Step-by-step explanation:
Here,
→ cosec A - cot A = 3/2 ----(1)
→ We know that,
cosec²A - cot²A = 1
So, (cosec A + cot A)(cosec A - cot A) = 1
So, (cosec A + cot A)(3/2) = 1 (From (1))
So, cosec A + cot A = 2/3 ----(2)
→ Now , add (1) and (2)
So,
cosec A - cot A = 3/2
cosec A + cot A = 2/3
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So, 2 cosec A = (3/2) + (2/3)
So, 2 cosec A = 13/6
So, cosec A = 13/12
So, sin A = 1/cosec = 12/13
→ Now, we have sin A = 12/13
sin A is positive. This means that A lies in either First or Second Quadrant.
We can find cot A easily to check which quadrant A lies in.
Putting cosec A = 13/12 in (2)
So, cosec A + cot A = 2/3
So, 13/12 + cot A = 2/3
So, cot A = 2/3 - 13/12
So, cot A = (8-12)/12
So, cot A = -5/12
• Now, cot A is negative. So A can either be in Second or Fourth Quadrant.
But, as sin A is also positive , A must lie in Second Quadrant.
→ Now,
cot A = cos A/sin A
So, cos A = cot A × sin A
So, cos A = (-5/12) × (12/13)
So, cos A = -5/13
→ Thus, cos A = -5/13, and A lies in Second Quadrant.
Hope it helps.
Step-by-step explanation:
the identity we use in this problem is cosec^2A-cot^2A=1=>
(cscA+cotA)(cscA-cotA) =1
(cscA+cotA)2/3=1
cscA+cotA=1÷2/3=3/2
therefore your answer is 3/2