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CUET
-- Mathematics - Section B1
Relations and Functions
If y=√x2−4cos−1(2−x), then the domain of y is :
[–2, 3]
[1, 2]
[2, 3]
[–2, 2]
We know that
x2−4≥0 and – 1 ≤ 2 – x < 1
x^2- 4 ≥ 0
⇒x^2≥4
|x|≥2
x≥2
x≤-2
– 1 ≤ 2 – x < 1
so 1 ≤ x ≤3
⇒ intersection of both of them gives
2 ≤ x ≤3⇒x∈[2,3] domain