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38 votes
Solve using quadratic formula q^2-2q-1=0

User Jassin
by
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1 Answer

27 votes
27 votes

Answer:

1±√2=q

or

q=2.41, -0.41

Explanation:

we are given the equation q²-2q-1=0, and we want to use the quadratic equation, which is (-b±√(b²-4ac))/2a

a is 1 (there is a 1 in front of q²)

b is -2

c is -1

substitute into the equation:

q=(2±√(4-4*1*-1))/2

solve for the discriminant:

√(4-4(1*-1))

√8

now the equation:

(2±√8)/2=q

simplify:

1±√2=q

or if your application asks for a decimal:

√2≈1.41

so:

1+1.41=2.41=q

or

1-1.41=-0.41=q

Hope this helps!

User SeanRamey
by
2.5k points