Solve 3x^2=-12-6x by completing the square
1 answer:
Answer:
x = - 1 ± i
Step-by-step explanation:
Given
3x² = - 12 - 6x ( add 6x to both sides )
3x² + 6x = - 12 ( divide through by 3 )
x² + 2x = - 4
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(1)x + 1 = - 4 + 1
(x + 1)² = - 3 ( take the square root of both sides )
x + 1 = ± = ± i
( subtract 1 from both sides )
x = - 1 ± i
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9514 1404 393
Answer:
38.5°
Step-by-step explanation:
A triangle solver can give an answer easily. The angle is 38.5°.
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The law of cosines can be written to solve for an unknown angle C opposite side 'c' and flanked by sides 'a' and 'b'.
C = arccos((a² +b² -c²)/(2ab))
Here, we have a=35, b=48, c=30, so the angle is ...
C = arccos((35² +48² -30²)/(2·35·48)) = arccos(2629/3360) ≈ 38.515°
The angle the cable makes with the pole is about 38.5°.
