let f(x) be aquaratic eqn which is positive for all real x.then

f(x)+f'(x)+f(x)is

a)>0

b)>=0

c)=0

d)<0

Dear Rohit

f(x)=ax² +bx+c

since it is positive for all x

a>0 and D<0==>b² - 4ac<0

f(x)+f'(x)+f"(x)=ax² +bx+c+ 2ax+b+2a=ax² +(2a+b)x+2a+b+c

D=(2a+b)² -4a(2a+b+c)=b²-4ac-4a² <0 and a>0

==>always positive

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