SOLUTION: Give exact and approximate solutions to three decimal places. {{{(x-2)^2=12}}} What are the exact solutions? x=___ (Type an exact answer, using radicals as needed. Rationaliz

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Question 394798: Give exact and approximate solutions to three decimal places.
%28x-2%29%5E2=12
What are the exact solutions?
x=___
(Type an exact answer, using radicals as needed. Rationalize all denominators. Express complex numbers in terms of i. Use a comma to separate answers as needed.)
What are the approximate solutions?
x=___
(Use a comma to separate answers as needed. Round to the nearest thousandth as needed.)

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

%28x-2%29%5E2=12
x%5E2+-+4x+%2B+4+=12
x%5E2+-+4x+%2B+4+-+12+=+0
x%5E2+-+4x+-+8+=+0
Solved by pluggable solver: Quadratic Formula
Let's use the quadratic formula to solve for x:


Starting with the general quadratic


ax%5E2%2Bbx%2Bc=0


the general solution using the quadratic equation is:


x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29




So lets solve x%5E2-4%2Ax-8=0 ( notice a=1, b=-4, and c=-8)





x+=+%28--4+%2B-+sqrt%28+%28-4%29%5E2-4%2A1%2A-8+%29%29%2F%282%2A1%29 Plug in a=1, b=-4, and c=-8




x+=+%284+%2B-+sqrt%28+%28-4%29%5E2-4%2A1%2A-8+%29%29%2F%282%2A1%29 Negate -4 to get 4




x+=+%284+%2B-+sqrt%28+16-4%2A1%2A-8+%29%29%2F%282%2A1%29 Square -4 to get 16 (note: remember when you square -4, you must square the negative as well. This is because %28-4%29%5E2=-4%2A-4=16.)




x+=+%284+%2B-+sqrt%28+16%2B32+%29%29%2F%282%2A1%29 Multiply -4%2A-8%2A1 to get 32




x+=+%284+%2B-+sqrt%28+48+%29%29%2F%282%2A1%29 Combine like terms in the radicand (everything under the square root)




x+=+%284+%2B-+4%2Asqrt%283%29%29%2F%282%2A1%29 Simplify the square root (note: If you need help with simplifying the square root, check out this solver)




x+=+%284+%2B-+4%2Asqrt%283%29%29%2F2 Multiply 2 and 1 to get 2


So now the expression breaks down into two parts


x+=+%284+%2B+4%2Asqrt%283%29%29%2F2 or x+=+%284+-+4%2Asqrt%283%29%29%2F2



Now break up the fraction



x=%2B4%2F2%2B4%2Asqrt%283%29%2F2 or x=%2B4%2F2-4%2Asqrt%283%29%2F2



Simplify



x=2%2B2%2Asqrt%283%29 or x=2-2%2Asqrt%283%29



So the solutions are:

x=2%2B2%2Asqrt%283%29 or x=2-2%2Asqrt%283%29





the exact solutions are
x1+=+2+%2B+2sqrt%283%29+=+2%2B2%2A1.73+=+2+%2B+3.46+=+5.46+

x2+=+2+-+2sqrt%283%29+=+2-2%2A1.73+=+2+-+3.46+=+-1.46+

the approximate solutions

x1+=+2+%2B+2sqrt%283%29+=+5.46+=+6
x2+=+2+-+2sqrt%283%29+=+-1.46+=+-2+