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Verified Answer :

f(x) = x^2 - 2x and g(x) = 6x + 4
(f + g)(x) = x^2 - 2x + 6x + 4 = x^2 + 4x + 4
(f + g)(x) = 0 => x^2 + 4x + 4 = 0
(x + 2)^2 = 0
x = -2

If f(x) = x² – 2x and g(x) = 6x + 4, the value of x which (f + g)(x) = 0 is -2

Further explanation

Function is a relation which each member of the domain is mapped onto exactly one member of the codomain.

There are many types of functions in mathematics such as :

  • Linear Function → f(x) = ax + b
  • Quadratic Function → f(x) = ax² + bx + c
  • Trigonometric Function → f(x) = sin x or f(x) = cos x or f(x) = tan x
  • Logarithmic function → f(x) = ln x
  • Polynomial function → f(x) = axⁿ + bxⁿ⁻¹ + ...

Recall the formulas related to the function such as :

\(( f + g )( x ) = f ( x ) + g ( x )\)

\(( f - g )( x ) = f ( x ) - g ( x )\)

\(( f \cdot g )( x ) = f ( x ) \cdot g ( x )\)

\(\left ( \frac{f}{g} \right )(x) = \frac {f(x)}{g(x)} ~, ~ where ~ g(x) eq 0\)

Let us now tackle the problem!

Given:

\(f(x) = x^2 - 2x\)

\(g(x) = 6x + 4\)

Unknown:

\(x = ?\)

Solution:

\(( f + g )( x ) = f ( x ) + g ( x )\)

\(( f + g )( x ) = (x^2 - 2x) + (6x + 4)\)

\(( f + g )( x ) = x^2 + 4x + 4\)

\(0 = x^2 + 4x + 4\)

\(0 = (x+2)^2\)

\(x + 2 = \sqrt{0}\)

\(\large { \boxed {x = -2} }\)

Learn more

  • Inverse of Function : https://brainly.com/question/9289171
  • Rate of Change : https://brainly.com/question/11919986
  • Graph of Function : https://brainly.com/question/7829758

Answer details

Grade: High School

Subject: Mathematics

Chapter: Function

Keywords: Function , Trigonometric , Linear , Quadratic

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