Question

Please answer the question from the attachment.

Answer 1

4 X^4 - 17 X² + 4 = 0
4( X²)²  - 17 X² + 4 = 0
X² = Y
4 Y²  - 17 Y + 4 = 0
Δ = b² - 4 .a.c
Δ = (-17)² - 4 .4.4
Δ = 289 - 64
Δ = 225 ⇒√225 = 15
y = - b + ou - 15/2.4
y´= -(-17) + 15/8 ⇒17 + 15 /8  ⇒32/8 = 4
x² = y
x² = 4  ⇒+ ou - √4  = +2;-2

y´´ = 17 - 15/ 8 ⇒ 2/ 8  = 1/4
x² = y
x² = 1/4
x = + ou - √1/4 = +1/2;-1/2
S = {+2 ; - 2 ; +1/2 ; - 1/2}