Question

Find the least positive value of k for which x2+kx+16 has real roots

Answer 1

Hello !!


The given equation is X²+KX + 16 = 0



Therefore,


Discriminant ( D ) = B²-4AC



=> [ (K)² - 4 × 1 × 16 ]



=> K² - 64



The given equation has real roots if D > 0.



Now,



D > 0 => K² - 64 > 0 => K² > 64




=> K > +8 or -8.



Hope it will help you ^_^

Answer 2

Answer,

Given equation => x² + kx + 16 = 0.

Now,

According to,

D = B² + 4AC

k² = 4 × 1 × 16

k² = 64

If D > 0 , the equation will have real roots....!!

Now,

D > 0 ,

k² - 64 > 0

k² > 64

K > +8 or -8 !!

Thanks!!