X4-7x2 plus 1 equals 0 what is the value of x?

Answer 1

The equation is a quadratic in x2, so using the quadratic formula:

x2 = [7 +/- √45]/2

so that x2 = 0.145898 or x2 = 6.854102

then x = √0.145898 = -0.381966 or +0.381966

or x = √6.854102 = -2.618034 or +2.618034