Math, asked by ojhaanshu3321, 1 year ago

Ques : What is the domain of the function f(x) = √(4-x^2)
Solution : Step-by-step explanation:

√(4-x^2) ≥ 0 [should be ]

(4-x^2) ≥ 0

4 ≥ x^2

2 ≥ x and x ≥ -2 .......(a)

So answer is domain [-2 , 2 ]
But, pls help me by explaining how equation (a) as i have marked came.... as per rules it should come -2 ≥ x instead of x ≥ -2
so, plss pls explain....

Answers

Answered by mkrishnan

Answer:

Step-by-step explanation:

HAI

if X and Y are positive and X < Y then X^2 < Y^2

if X and Y are negative and X < Y then X^2 > Y^2

if XY > 0 then X and Y are both positive or both negative

if XY < 0 then smaller one is negative and other is positive

if [x-2] [x+2] < 0 then the smaller is here x-2 is negative

the other is positive

x-2<0 and x+2>0

x< 2 and x > -2

ojhaanshu3321: No, but take x = 6 for instance

ojhaanshu3321: Then ( x-2)(x+2) = (6-2)(6+2) = 4 × 8

ojhaanshu3321: So, according to your explanation i should take 4 as -ve and 8 (larger one) as positive

ojhaanshu3321: But, iys not so, if 8 is here -ve and 4 is +ve then also we are getting product as -32 which is less than 0

ojhaanshu3321: So, i think your explanation, Mkrishnan sir, is not so correct

ojhaanshu3321: I request you pls explain me in that sense

ojhaanshu3321: Pls, explain me sir

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