Latest TCS Aptitude Question SOLUTION: For a,b,c R if ax^2+ bx+c is real for real values of x and imaginary for imaginary values of x then: a) a > 0 b) a < 0 c) a = 0 d) None of these

• Placement Papers
• /
• TCS

TCS Question Papers: TCS Interview Experience(90) TCS Company Profile

(#M40012237) TCS question Keep an EYE

For a,b,c R if ax^2+ bx+c is real for real values of x and imaginary for imaginary values of x then:
a) a > 0 b) a < 0 c) a = 0 d) None of these

Asked In TCS Swapnil Deshmukh (11 years ago)

Unsolved Read Solution (3)

Is this Puzzle helpful?   (3)   (3) Submit Your Solution

Read Solution (3) :

shyam salona  (11 years ago)

ax^2+bx+c=x(ax+b)+c
as a,b,c are real
if x is real then expression will be real for all value of x
but
if x is imaginary then expression will be imaginary only when one of x and ax+b
is real if we consider all value of x
so x can't be real (given imaginary)
then ax+b should be real
so a=0 ans.

Is this solution Helpfull? Yes (18) | No (6)  

Swatantra Jain  (11 years ago)

when x is real
for any value of a either its >,< or = 0 expression will be real
and when x is imaginary
for any value of a it will be imaginary
on the other hand for b=0 expression will be real for even imaginary value of x
So, the expression is dependent on b for being real or imaginary not on a
hence ans is d) None of these

Is this solution Helpfull? Yes (4) | No   

Tabrez Siddiqui  (11 years ago)

c) a=0.
if b= real value => b+c real
if b= 2+3i => b+c =(2+c)+3i

Is this solution Helpfull? Yes (2) | No (8)  

Please Login to Read Solution.