SOLUTION: Find all real solutions for x^4-5x^2+4=0

Question 17533: Find all real solutions for x^4-5x^2+4=0
Answer by xcentaur(357) (Show Source): You can put this solution on YOUR website!
x^4-5x^2+4=0

Let y=x^2

Then we get:
y^2-5y+4=0
(y-4)(y-1)=0
Therefore y=4,1
Therefore x^2=4 or 1
Since squares of negative numbers are also positive,we get:
x=+2,-2,+1,-1
Now out of these,-1 and -2 are both less than zero,ie.non-real

Hence real solutions for x will be:
x=1,2

Hope this helps,
Prabhat
RELATED QUESTIONS
Find all real solutions: x-5x^1/2+4=0 How would you solve this... (answered by mananth)

Find all real solutions:... (answered by josmiceli)

find all real solutions of the equation.... (answered by jim_thompson5910)

Find all real solutions:... (answered by Alan3354)

Find all real solutions to the equation 4^x - 5(2^x) - 24 =... (answered by Alan3354)

Find all solutions for: 4 sin^2 x - 3 =... (answered by lwsshak3)

Find all real solutions of the equation. {{{ x^4-8x^2-9=0... (answered by KMST)

x^4-10x^2+25=0 find all real and complex... (answered by Fombitz,Alan3354)

Find all real solutions of the equation. x^2 + 5x - 6 = 0 (answered by ewatrrr)