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If domain of the function loge6x2+5x+12x-1+cos-12x2-3x+43x-5 is α,βγ,δ, then 18α2+β2+γ2+δ2 is equal to
MathematicsFunctionsJEE MainJEE Main 2023 (08 Apr Shift 2)
Solution:
1861 Upvotes Verified Answer
The correct answer is: 20

We need to find the domain of the function loge6x2+5x+12x-1+cos-12x2-3x+43x-5.

6x2+5x+12x-1>0 .....(1) and

 -12x2-3x+43x-51......(2)
Now From 1,
6x2+5x+12x-1>0

(3x+1)(2x+1)(2x-1)>0

Now we get the common region here as
x-12,-1312,.......(a)

From 2 we get that
-12x2-3x+43x-51

2x2-3x+43x-5-1......3

and 2x2-3x+43x-51.....4

From 3 we get
2x2-3x+43x-5+10

x-12,1253,.....b

From 4 we get
2x2-3x+43x-5-10

2x2-6x+93x-50

As D=-62-429<0 and 2>0, we observe that 2x2-6x+9>0 x
13x-50  2x2-6x+9>0xR

  x-,53   ......c

Intersection of (a), (b) and (c) gives us
x-12,-1312,12.

On comparing this with α,βγ,δ,
α2+β2+γ2+δ2=109
18α2+β2+γ2+δ2=20.

Hence this is the required answer.

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