TCS
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Numerical Ability
Age Problem
If x^2-16>0,which of the following must be true nd how?
a)-4>x>4
b)-4>x
Read Solution (Total 14)
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- for inequalities when you are taking square root of number remember following rules
for x^2>16
as x can be either positive or negative hence consider following cases
1] if x is positive then x > 4 (no change of inequality)
2] if x is negative then x < -4 (change of inequality)
hence -4 > x > 4 is the correct answer but on TCS openseeme they given the wrong answer - 12 years agoHelpfull: Yes(32) No(2)
- (a^2-b^2)=(a+b)(a-b)
X^2-16=(x+4)(x-4)
x+4=0 -->x=-4
x-4=0 -->x=4
so value of x lies between 4 and -4
so a)is right ans - 12 years agoHelpfull: Yes(13) No(16)
- the equation will be satisfy only if
x belongs to (-infinity , -4)and (4 , infinity)
values of option A is not satisfying equation.
so the ans is option B. - 12 years agoHelpfull: Yes(12) No(8)
- x2-16>0
x2>16
then x>-+4
hence it is lies between -4>x>4 - 12 years agoHelpfull: Yes(7) No(4)
- x^2-4^2>0
(x+4)(x-4)>0
x+4>0,x-4>0
- 12 years agoHelpfull: Yes(4) No(5)
- x^2-16>0
x^2-4^2>0
(x-4)(x+4)>0
x>4
x>-4
so the answer is a)-4>x>4
- 12 years agoHelpfull: Yes(2) No(11)
- its option [a] such a simple Q_ :)
- 12 years agoHelpfull: Yes(1) No(17)
- x^2-16>0
(x-4)(x+4)>0
then the value of x is selected such that X>4 and X0
also -ve value of x say -5 then (-5)^2 -16=9>0
so x>4 and x - 12 years agoHelpfull: Yes(1) No(4)
- for x= -4 ans is not > than 0 but for value less than -4 it is > than 0
- 12 years agoHelpfull: Yes(1) No(5)
- The equation will satisfy for all numbers >4 and >-4. Hence the right answer will be X = >+/-4
- 11 years agoHelpfull: Yes(1) No(0)
- but is it ever possible that a number is less than -4 but greater than 4 , plz rectify me
- 10 years agoHelpfull: Yes(0) No(0)
- (x-4)(x+4)>0
so,(x-4)>0 and (x+4)>0
then
x>4 and x - 10 years agoHelpfull: Yes(0) No(0)
- the answer must be x4
- 10 years agoHelpfull: Yes(0) No(0)
- x^2-16>0
x=+-4
so x lies b/w -4and+4
so ans is -4>x>+4 - 9 years agoHelpfull: Yes(0) No(0)
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