How do you find the discriminant and how many solutions does x^2+4x+3=4 have?

2 Answers
Sonnhard
Jun 8, 2018

We get two real solutions

Explanation:

Writing your equation in the form
x^2+4x-1=0
the4n we get by the quadratic formula:

x_{1,2}=2pm\sqrt(4+1)
so we get
x_1=2+sqrt(5)

x_2=2-sqrt(5)

Nghi N.
Jun 8, 2018

x = -2(1 +- sqrt5)

Explanation:

x^2 + 4x + 3 = 4
f(x) = x^2 + 4x - 1 = 0
Discriminant D -->
D = d^2 = b^2 - 4ac = 16 + 4 = 20 --> d = +- 4sqrt5
There are 2 real roots:
x = -b/(2a) +- d/(2a) = -4/2 +- (4sqrt5)/2 = - 2 +- 2sqrt5

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