Question

prove that x2 +2x+3 has no zero

Answer 1

Heyy !
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x² + 2x + 3 
here a = 1 
        b = 2 
        c = 3 
D = b² - 4ac 
   = 4   - 4 x 3 
   = -8 
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Here D ≤ 0 
So it has no real roots 
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Answer 2

Hey there !!!

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A quadratic equation of the form ax²+bx+c=0 has no real zeroes when discriminant of equation is < 0
                        ⇒⇒  b²-4ac< 0

Comparing x²+2x+3=0 with ax²+bx+c=0 

a=1 b=2 c=3 

=b²-4ac

= 2²-4*3

4-12=-8 < 0

As discriminant is less than zero x²+2x+3=0 will have no real roots.

Hope this helped you...........