Question

If a= 2 + √3, find the value of a-1/a
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Answer 1

Answer:

A=2+√3

∴, 1/a=1/(2+√3)=(2-√3)/(2+√3)(2-√3)=(2-√3)/(4-3)=2-√3

∴, a+1/a=2+√3+2-√3=4

now, a²=(2+√3)²=4+4√3+3=7+4√3

1/a²=(1/a)²=(2-√3)²=4-4√3+3=7-4√3

∴, a²+1/a²=7+4√3+7-4√3=14