Question

if x^4-142x^2+1=0then find the value of x?​

Answer 1

Answer:

x⁴ - 142x² + 1= 0

if assume

x² = y

then

y² - 142y + 1 = 0

by using the quadratic formula

y = [-b ± √b²-4ac ]/ 2a

y = {-(-142)±√(142)²-4.1.1} / 2.1

y = 142±√1704-4 / 2

y = 142±√1700 / 2

y = 142±10√17 / 2

y = 71±5√17

We taking (+) sign (-) sign

y = 71+5√17 y=71-5√17

x² = 71+5√17 x²=71-5√17

x = √71+5√17 , x= √71-5√17