if the product of zeroes of the quadratic polynomial 3x^2+5x+k is -2/3, find the value of k
Answers
Answered by
12
X= -2/3
q(x) = 3x^2+5x+k
Put x= -2/3 in q(x)
q(-2/3) = 3(-2/3)^2+5(-2/3)+k = 0
= 3(4/9) + (-10/15) + k = 0
= 4/3 - 10/15 + k = 0
= (20 - 10 + 15k)/15 = 0
= 20 - 10 + 15k = 0*15
= 10 + 15k = 0
= 15 k = -10
= k = -10/15
= k = -2/3
q(x) = 3x^2+5x+k
Put x= -2/3 in q(x)
q(-2/3) = 3(-2/3)^2+5(-2/3)+k = 0
= 3(4/9) + (-10/15) + k = 0
= 4/3 - 10/15 + k = 0
= (20 - 10 + 15k)/15 = 0
= 20 - 10 + 15k = 0*15
= 10 + 15k = 0
= 15 k = -10
= k = -10/15
= k = -2/3
Answered by
21
Answer:
K= -2
Given
P(x)= 3x2+5x+k , product of zeroes = -2/3 ⇒ αβ= -2/3
αβ = c/a
⇒ -2/3=c/a
according to the question,
c/a= k/3
CROSS MULTIPLY
= -2/3=k/3
k = -2
thnx
Similar questions