414,213 views
35 votes
35 votes
Given that g(x)=3x-7
Find the value of k

g^(2) (4k/3)=8

User Vamsi Bitra
by
2.1k points

1 Answer

21 votes
21 votes

Answer:

{
(7)/(4) -
(√(2) )/(2) ,
(7)/(4) +
(√(2) )/(2) }

Explanation:

ax² + bx + c = 0


x_(12) = ( - b ±
√(b^2 -4ac) ) ÷ 2a

~~~~~~~~~~~

g(x) = 3x - 7

g²(x) = (3x - 7)²

g²(x) = 9x² - 42x + 49

g²(
(4k)/(3) ) = 9(
(4k)/(3) )² - 42(
(4k)/(3) ) + 49

9(
(4k)/(3) )² - 42(
(4k)/(3) ) + 49 = 8

16k² - 56k + 41 = 0

a = 16 , b = - 56 , c = 41

D = b² - 4ac = ( - 56)² - 4(16)(41) = 512 =
2^(9)


k_(1) = ( 56 + √
2^(9) ) ÷ 32 =
(7)/(4) +
(√(2) )/(2)


k_(2) =
(7)/(4) -
(√(2) )/(2)

User Nachum
by
3.1k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.