If a=root5+3/root5-3 and b = root5 -3/ root 5+ 3 then find the value of a2 +b2 +ab
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Answer:
a=(√5+3)/(√5-3)
b=(√5-3)/(√5+3)
ab=(√5+3)/(√5-3)×(√5-3)/(√5+3)=1
a+b=(√5+3)/(√5-3)+(√5-3)/(√5+3)
=(√5+3)^2+(√5-3)^2/(√5+3)((√5-3)
=(5+9+6√5+5+9-6√5)/(√5^2-3^2)
=28/(5-9)
=28/-4
= -7
a^2+b^2+ab
=(a+b)^2-2ab+ab
=(-7)^2-ab
=49-1
=48
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