Alpha & beta are zeroes of polynomial 2x^2-4x+5 , find the value of 1\alpha + 1\beta & 1\alpha square + 1\beta square
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Given, 2x ² - 4x + 5
Here, a = 2; b = -4; c = 5
p + q(Sum of roots) = -b/a
==> 4/2
p + q = 2............(1)
Next,
pq( product of roots ) = c/a
==> 5/2............(2)
( Ⅰ )
1/p + 1/q
==> p + q/pq
==> 2 ÷ 5/2
==> 2 × 2/5
==> 4/5
Therefore, 1/p + 1/q = 4/5
( Ⅱ )
1/p ² + 1/q ²
==> p ² + q ²/p ²q ²
==> (p + q) ² - 2pq/(pq) ²
==> (2) ² - 2 × 5/2 ÷ (5/2) ²
==> 4 - 5 ÷ 25/4
==> -1 × 4/25
==> -4/25
Therefore, 1/p ² + 1/q ² = -4/25
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