Difference between revisions of "Sub-Problem 2"

Revision as of 17:52, 22 March 2021

(b) Determine all (a,b) such that:

From equation 2, we can acquire ab = 100

We can then expand both sides by squaring:

$(\sqrt{a} + \sqrt{b})^2 = (8)^2$ $(a + b + 2 \sqrt{ab}) = 64$

since ab = 100: 2root(ab) is 2root(100), which is 20.

We can get the below equation:

$(a + b) = 44$ $(ab) = 100$

Substitue b = 44 - a, we get

$((44-a)a) = 100$ $(44a - a^2 - 100) = 0$

By quadratic equations Formula:

${a=\frac{-44 \pm \sqrt{44^2-4(-1)(-100)}}{2(-1)}}$

${a=\frac{44 \pm \sqrt{1536}}{2(1)}}$

which leads to the answer of 22 +- 8root(6)

Since a = 44 - b, two solutions are:

$(a,b) = ($ (8 \sqrt{6) + 22),$$ (Error compiling LaTeX. Unknown error_msg)(-8 \sqrt{6} + 22))

~NAMCG

@@ Line 7: / Line 7: @@
 == Solution 1 ==
 From equation 2, we can acquire ab = 100
 We can then expand both sides by squaring:
-(
+<cmath>(\sqrt{a} + \sqrt{b})^2 = (8)^2</cmath>
+<cmath>(a + b + 2 \sqrt{ab}) = 64</cmath>
+since ab = 100: 2root(ab) is 2root(100), which is 20.
+We can get the below equation:
+<cmath>(a + b) = 44</cmath>
+<cmath>(ab) = 100</cmath>
+Substitue b = 44 - a, we get
+<cmath>((44-a)a) = 100</cmath>
+<cmath>(44a - a^2 - 100) = 0</cmath>
+By quadratic equations Formula:
+<math>{a=\frac{-44 \pm \sqrt{44^2-4(-1)(-100)}}{2(-1)}}</math>
+<math>{a=\frac{44 \pm \sqrt{1536}}{2(1)}}</math>
+which leads to the answer of 22 +- 8root(6)
+Since a = 44 - b, two solutions are:
+<cmath>(a,b) = (</cmath>(8 \sqrt{6) + 22),<math></math>(-8 \sqrt{6} + 22))
 == Video Solution ==