Question

solve for x:
x^4-14x^2+13=0

Answer 1

\[x^4-14x^2+13=0\]

Answer 2

do you know how to solve this equation?
\[y^2-14y+13 = 0\]

Answer 3

mmmmm not really is cuz they gave us a reviw nd i dont remember anything from last year

Answer 4

starting with your original problem, lets substitute y = x^2 into it. then we get the equation i posted above.

To solve, you want to think of two numbers that multiply to 13, but add to make -14.

Those two numbers are -13 and -1.

so we have:
\[y^2-14y+13 = (y-13)(y-1) = 0 \iff y = 13 , y = 1\]
but now lets put back our substitution:
\[y = 13 \iff x^2 = 13 \iff x = \pm \sqrt{13}\] and
\[y = 1 \iff x^2 = 1 \iff x = \pm 1\]

Answer 5

ok thanks a lot =)