SOLUTION: One definition of phi suggests that it is equal to the larger of the two roots of the polynomial. Write roots in both exact and decimal forms (round to the nearest hundredths) x

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: One definition of phi suggests that it is equal to the larger of the two roots of the polynomial. Write roots in both exact and decimal forms (round to the nearest hundredths) x      Log On


   

Question 1161298: One definition of phi suggests that it is equal to the larger of the two roots of the polynomial. Write roots in both exact and decimal forms (round to the nearest hundredths)
x2 - x - 1 = 0
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
+x%5E2+-+x+-+1+=+0....use quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-%28-1%29+%2B-+sqrt%28+%28-1%29%5E2-4%2A1%2A%28-1%29%29%29%2F%282%2A1%29+
x+=+%281+%2B-+sqrt%28+1%2B4%29%29%2F2+
x+=+%281+%2B-+sqrt%28+5%29%29%2F2+
roots: in exact form
x+=+1%2F2+%2B+sqrt%28+5%29%2F2+
x+=+1%2F2+-sqrt%28+5%29%2F2+
or in decimal form:
x+=+1.62
x+=+-0.62+