⎩ ⎨ ⎧ sin ( lo g 2 ∣ z ∣ ) > 0 ∣ z ∣ < 1
If A be the total area satisfied by the region of the curves as shown above. Find the sum of all the integral solutions of ∣ x 2 − 4 ∣ + ∣ x 2 − 1 ∣ = ⌊ A + 3 ⌋ , where z is a complex number.
Where sine is in the 1st set of quadrants, Namely ( 0 → 2 π ), ( 2 π → π ), ( π → 2 3 π ), ( 2 3 π → 2 π )
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We need to find the area satisfying both the curves
Now see sin ( lo g 2 ∣ z ∣ ) > 0 means lo g 2 ∣ z ∣ lies in ( 0 , π ) .
⟹ 0 < lo g 2 ∣ z ∣ < π
⟹ 1 < ∣ z ∣ < 2 π
Now see that another equation is ∣ z ∣ < 1 , but from the above curve we have got ∣ z ∣ > 1 . So , the area cannot be founded. It is simply 0 .
See these curves in desmos
So A = 0
⟹ ∣ x 2 − 4 ∣ + ∣ x 2 − 1 ∣ = ⌊ 0 + 3 ⌋
⟹ . ∣ x 2 − 4 ∣ + ∣ x 2 − 1 ∣ = 3
Now lets try to divide them in intervals and solve these.
Case 1
When
x
≥
2
⟹
x
2
−
4
+
x
2
−
1
=
3
o
r
x
=
2
Case 2 In the region 2 > x ≥ 1 . ⟹ − x 2 + 4 + x 2 − 1 = 3 ⟹ x = 1 as here for any x , we can satisfy, But we need the integral one,
Case 3 In the region 1 > x ≥ − 1 .
⟹ − x 2 + 4 − x 2 + 1 = 3 ⟹ x = − 1 after solving
Case 4
Now again in the interval
−
1
>
x
≥
−
2
⟹
−
x
2
+
4
+
x
2
−
1
=
3
⟹
There is no solutions
Case 5
When x ≤ − 2
x 2 − 4 + x 2 − 1 = 5
⟹ x = − 2
So Adding all we get S u m = 0
You are wrong sir, the log term can also lie in (-2pi, -pi) , also in (-4pi, -3pi) , so u get infinite solutions, and calculating the area you get around 0.04 square units. However you dont even need to calculate the value of A , becuz for every solution of x, you have the additive inverse '-x' as a solution too since the function is even, hence the sum is zero, independent of value of A.
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No, i have mentioned above that it will work for only the first set of quadrants .. Now ? Am i correct?
@Md Zuhair You may ask the sum of modulus values of roots or product of the roots.
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You dont even need to calculate the value of A, since for every solution 'x' , there is a solution '-x' too since the equation is even in x or symmetric about x=0 , hence the sum of solutions would be zero independent of the value of A