Find all value of x € ( 0 , π / 2 ) such that
Answers
Answer:
Hey there
refer to attachment
Question :--- Find all value of x € ( 0 , π / 2 ) such that (√3-1/sinx) + (√3+1/cosx) = 4√2 ..
Solution :----
→ (√3-1/sinx) + (√3+1/cosx) = 4√2
Taking LCM of LHS, we get,
→ [ (√3-1)*cosx + (√3+1)*sinx ] /sinx * cosx = 4√2
Taking Denominator RHS now, we get,
→ [ (√3-1)*cosx + (√3+1)*sinx ] = 4√2 * sinx * cosx
Dividing both sides by 2√2 now , we get,
→ [ (√3-1/2√2) * cosx + (√3+1/2√2)*sinx ] = 2 * sinx * cosx .
______________________________
Now, we know that,
[ → (√3-1/2√2) = sin15° = sin(π/12)
[ → (√3-1/2√2) = sin15° = sin(π/12)→ (√3+1/2√2) = cos15° = cos(π/12)
[ → (√3-1/2√2) = sin15° = sin(π/12)→ (√3+1/2√2) = cos15° = cos(π/12) → 2 * sinx * cosx = sin2x
[ → (√3-1/2√2) = sin15° = sin(π/12)→ (√3+1/2√2) = cos15° = cos(π/12) → 2 * sinx * cosx = sin2x → SinA*cosB + cosA*SinB = sin(A+B) ]
______________________________
using all these values in Question now, we get,
→ Sin(π/12) * cosx + cos(π/12)* sinx = sin2x
→ sin(x + π/12) = sin2x
→ 2x = nπ + (-1)^n ( x + π/12)
So, now putting n = 0, we get,
→ 2x = 0 + 1(x + π/12)
→ 2x = (x+π/12)
→ 2x - x = π/12
→ x = π/12 .
And, if n = 1 ,
→ 2x = π + (-1)(x + π/12)
→ 2x = π - x - π/12
→ 3x = 11π/12