Math, asked by taadinejt5ziy, 1 year ago

Evaluate :{√(5+2√6)} +{√(8-2√15)}

Answers

Answered by kvnmurty
73
let\ \sqrt{5+2\sqrt6}=\sqrt{a}+\sqrt{b}\\\\squaring:\ 5+2\sqrt6=a+b+2\sqrt{ab}\\\\equate\ rational\ and\ irrational\ parts\\\\a+b=5,\ ab=6,\ easy\ to\ know:a=3,\ b=2,\ or\ a=2,b=3\\\\let\ \sqrt{8-2\sqrt{15}}=\sqrt{c}-\sqrt{d},\ minus\ as\ there\ is\ - inside\ square\ root.\\\\squaring\ 8-2\sqrt{15}=c+d-2\sqrt{cd}\\\\ \implies\ c+d=8,\ cd=15\\\\Easy\ to\ know,\ c=5, d=3\ or\ c=3,\ d=5\\\\but\ we\ take\ positive\ square\ root.\\\\Answer=\sqrt{2}+\sqrt{3}+\sqrt{5}-\sqrt{3}=\sqrt{2}+\sqrt{5}

====
We can also find the values of  a, b  or c, d  by solving quadratic equations.

c + d = 8   and  c d = 15   =>  d = 15/c
=>  c + 15/c = 8
=>  c² - 8 c + 15 = 0
=>   c² - 5 c - 3 c + 15 = 0
=>   (c - 5) c - 3 ( c - 5) = 0
=>   (c - 5) ( c - 3) = 0          => c = 5 or 3
=>  d = 3 or 5

kvnmurty: clik on thanks.
Anonymous: excellent answer sir keep it up!!!!!!!!!!!!!!!!!!!
Answered by rashmirjain
1

Answer:

HEY MATE!!  HOW DO U DO

THE ANSWER ISSSSSSSSS

I DON'TTTTTT KNOWWWWW!! I AM SORRY BRO

Step-by-step explanation:

Similar questions