Question

If the sum of zeros 3x² - kx +6 is 6 find the value of k? ​

Answer 1

Question  :

If the sum of zeros 3x² - kx +6 is 6 find the value of k? ​

Solution :

Given equation ; 3x² - kx + 6

Sum of zeros = 6

Required to find ; value of k

Sum of zeros of a quadratic polynomial is given by,

$\longmapsto\boxed{\boxed{\bold{Sum \ of \ zeros = \dfrac{- coefficient \ of \ x \ (b)}{coefficient \ of \ x^2 \ (a)} }}}$

Here comparing the given equation with ax² + bx + c we get,

1. a = 3
2. b = -k
3. c = 6

Now putting values,

$\longmapsto\sf 6 = \dfrac{-(-k)}{3} \\\\ \\ \longmapsto\sf 6 = \dfrac{k}{3} \\\\ \\ \longmapsto\sf k = 6 \times 3 \\\\ \\ \longmapsto\boxed{\boxed{\bold{k = 18 }}} \ \bigstar$

$\therefore\underline{\boxed{\bf{Required \ value \ of \ k = 18 }}}$