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Find all complex solutions of 3x^2+3x+4=0.

(If there is more than one solution, separate them with commas.)

1 Answer

5 votes
Given equation is
3x^2 + 3x + 4 = 0

Now we can compare it with general form of quadratic equation (
ax^2 + bx + c = 0)
a = 3 , b = 3 and c = 4

Now we can apply quadratic formula which is given as

x =( -b+/- √(b^2-4ac) )/(2a)

Now we can plugin value of a , b or c

x = (-3+/- √((3)^2 - 4*3*4) )/(2*3)

= (-3+/- √(9 - 48) )/(6) = (-3+/- √(-39) )/(6)
In general we know
√(-1) = i
So we can write
√(-39 ) = √(-1) * √(39) = i √(39)
So

x = (-3+/-i √(39) )/(6)
So
x = (-3+i √(39) )/(6) or
x = (-3- √(39) )/(6)
User PzYon
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