SOLUTION: finding zeros of a polynomial function f(x)=5x^4+15x^2 +10

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Question 655345: finding zeros of a polynomial function f(x)=5x^4+15x^2 +10

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=5x%5E4%2B15x%5E2+%2B10+
f%28x%29=5%28x%5E4%2B3x%5E2%2B2%29+
f%28x%29=5%28x%5E4%2B2x%5E2%2Bx%5E2%2B2%29+

f%28x%29=5%28%28x%5E4%2B2x%5E2%29%2B%28x%5E2%2B2%29%29+
f%28x%29=5%28x%5E2%28x%5E2%2B2%29%2B%28x%5E2%2B2%29%29+
f%28x%29=5%28x%5E2%2B1%29%28x%5E2%2B2%29%29+
set f%28x%29=0 to fins solutions:
if %28x%5E2%2B1%29+...->....x%5E2=-1+.->....x=-i+ or x=i+..complex roots
if %28x%5E2%2B2%29=0+...->....x%5E2=-2+...->....x%5E2=sqrt%28-2%29...->....x=-i%2Asqrt%282%29+ or x=i%2Asqrt%282%29+....complex roots
so, roots are: complex roots
x=-i+
x=i+
x=-i%2Asqrt%282%29+
x=i%2Asqrt%282%29+