If $(a+1/a-3)^2=36$then find $a^2+1/a^2$

Challenger App

★

1M+ Downloads

If $(a+1/a-3)^2=36$ then find $a^2+1/a^2$

A82

B83

C81

D79

Answer:

$(a+1/a-3)^2=36$

$a+1/a-3=\sqrt{36}=6$

$a+1/a-3=6$

$a+1/a=6+3=9$

$a^2+1/a^2=9^2-2$

$=81-2=79$

if $a+1/a=k$ then $a^2+1/a^2=k^2-2$

Related Questions:

If $x^4+\frac{1}{x^4}=34$ , then the value of $(x-\frac{1}{x})^2$ will be

If (a + b + c) = 17, and (a²+ b² + c²) = 101, find the value of (a - b)² + (b - c)² + (c - a)².

If $x ^ 2 + 1 / x ^ 2 = 7$ find the value of $x + 1 / x$