MHB Simplifying [(x2 - 4)(x2 + 3)1/2] - [(x2 - 4)2(x2 + 3)3/2]

  • Thread starter Thread starter PaperStSoap
  • Start date Start date
  • Tags Tags
    Simplify
AI Thread Summary
The discussion focuses on simplifying the expression [(x^2 - 4)(x^2 + 3)^(1/2)] - [(x^2 - 4)^2(x^2 + 3)^(3/2)]. The first half of the expression simplifies to (x - 2)(x + 2)(x^2 + 3)^(1/2). Participants suggest factoring out the greatest common factor, which is (x^2 - 4)(x^2 + 3)^(1/2). The final simplified form includes the factor (13 + x^2 - x^4). The conversation emphasizes the importance of identifying common factors for simplification.
PaperStSoap
Messages
9
Reaction score
0
[(x2 - 4)(x2 + 3)1/2] - [(x2 - 4)2(x2 + 3)3/2]

I understand the first half which comes out to...

(x-2)(x+2)(x2 + 3)1/2 I have know idea how to start the second half.

Thanks in advance.
 
Mathematics news on Phys.org
PaperStSoap said:
[(x2 - 4)(x2 + 3)1/2] - [(x2 - 4)2(x2 + 3)3/2]

I understand the first half which comes out to...

(x-2)(x+2)(x2 + 3)1/2 I have know idea how to start the second half.

Thanks in advance.

Look for the greatest common factor of the two terms, in this case that is \(x^2-4)(x^2+3)^{1/2}\), so:
\[\begin{aligned}\left((x^2 - 4)(x^2 + 3)^{1/2}\right) - \left((x^2 - 4)^2(x^2 + 3)^{3/2}\right)&=(x^2-4)(x^2+3)^{1/2}\left(1-(x^2-4)(x^2+3) \right)\\
&=(4-x^2)(x^2+3)^{1/2}\left((x^2-4)(x^2+3)-1 \right) \end{aligned}\]

CB
 
Hello, PaperStSoap!

\text{Simplify: }\: (x^2-4)(x^2+3)^{\frac{1}{2}} - (x^2-4)^2(x^2+3)^{\frac{3}{2}}
Factor: .$(x^2-4)(x^2+3)^{\frac{1}{2}}\cdot\big[1 - (x^2-4)(x^2+3)\big] $

. . . . $=\;(x^2-4)(x^2+3)^{\frac{1}{2}}\cdot\big[1 - x^4 + x^2 + 12\big]$

. . . . $=\;(x^2-4)(x^2+3)^{\frac{1}{2}}\left(13 + x^2 - x^4\right)$
 
Seemingly by some mathematical coincidence, a hexagon of sides 2,2,7,7, 11, and 11 can be inscribed in a circle of radius 7. The other day I saw a math problem on line, which they said came from a Polish Olympiad, where you compute the length x of the 3rd side which is the same as the radius, so that the sides of length 2,x, and 11 are inscribed on the arc of a semi-circle. The law of cosines applied twice gives the answer for x of exactly 7, but the arithmetic is so complex that the...
Back
Top