Question

To show how to solve the equation, create two functions and find their intersection points. What two functions can be used to solve the following equation, and what is their solution set?

x2+4x−1=2x+2


(1 point)

f(x)=x2+4x
, g(x)=2x
, {−3,1}


f(x)=x2+4x−1
, g(x)=2x+2
, {−3,1}


f(x)=x2+4x−1
, g(x)=2x+2
, {−3,−4,1,4}


f(x)=x2+4x−1
, g(x)=2x+2
, {−1,3}

Answer 1

Use the two sides as functions: f(x) = x^2 + 4x − 1 and g(x) = 2x + 2.
Set f(x) = g(x): x^2 + 4x − 1 = 2x + 2 → x^2 + 2x − 3 = 0 → (x + 3)(x − 1) = 0.
So x = −3 or x = 1.

Answer: f(x)=x^2+4x−1, g(x)=2x+2, solution set {−3, 1}.