SOLUTION: Hello. Find all x that will make f(x)= 0 f(x)= x^2 + 2x

SOLUTION: Hello. Find all x that will make f(x)= 0 f(x)= x^2 + 2x - 4 thanks!

Question 189935: Hello.
Find all x that will make f(x)= 0
f(x)= x^2 + 2x - 4
thanks!

Found 2 solutions by jim_thompson5910, stanbon:
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!

Start with the given equation.

Plug in

Notice we have a quadratic equation in the form of where , , and

Let's use the quadratic formula to solve for x

Start with the quadratic formula

Plug in , , and

Square to get .

Multiply to get

Rewrite as

Add to to get

Multiply and to get .

Simplify the square root (note: If you need help with simplifying square roots, check out this solver)

Break up the fraction.

Reduce.

or Break up the expression.

So the answers are or

which approximate to or

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Find all x that will make f(x)= 0
f(x)= x^2 + 2x - 4
------------------------
x^2+2x-4 = 0
Use the quadratic formula to get:
x = [-2 +- sqrt(2^2 - 4*1*-4)]/2
---
x = [-2 +- sqrt(20)]/2
x = [-2 +- 2sqrt(5)]/2
x = [-1 +- sqrt(5)]
============================
Cheers,
Stan H.
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