SOLUTION: please help me solve 2x^4+15x^2-8=0

Algebra ->  Equations -> SOLUTION: please help me solve 2x^4+15x^2-8=0      Log On


   

Question 587592: please help me solve 2x^4+15x^2-8=0
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+2x%5E4%2B15x%5E2-8=0+
You can use the quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
+a+=+2+
+b+=+15+
+c+=+-8+
x+=+%28-15+%2B-+sqrt%28+15%5E2-4%2A2%2A%28-8%29+%29%29%2F%282%2A2%29+
x+=+%28-15+%2B-+sqrt%28+225+%2B+64+%29%29+%2F+4+
x+=+%28-15+%2B-+sqrt%28+289+%29%29+%2F+4+
x+=+%28-15+%2B+17+%29+%2F+4+
+x+=+2%2F4+
+x+=+1%2F2+
and, using the negative root,
x+=+%28-15+-+17+%29+%2F+4+
+x+=+-32%2F4+
+x+=+-8+
These are the 2 solutions