Solution - Equations reducible to quadratic form
Other Ways to Solve
Equations reducible to quadratic formStep by Step Solution
Step by step solution :
Step 1 :
Equation at the end of step 1 :
((x6) - (23•53x3)) + 8000 = 0
Step 2 :
Trying to factor by splitting the middle term
2.1 Factoring x6-1000x3+8000
The first term is, x6 its coefficient is 1 .
The middle term is, -1000x3 its coefficient is -1000 .
The last term, "the constant", is +8000
Step-1 : Multiply the coefficient of the first term by the constant 1 • 8000 = 8000
Step-2 : Find two factors of 8000 whose sum equals the coefficient of the middle term, which is -1000 .
-8000 | + | -1 | = | -8001 | ||
-4000 | + | -2 | = | -4002 | ||
-2000 | + | -4 | = | -2004 | ||
-1600 | + | -5 | = | -1605 | ||
-1000 | + | -8 | = | -1008 | ||
-800 | + | -10 | = | -810 |
For tidiness, printing of 50 lines which failed to find two such factors, was suppressed
Observation : No two such factors can be found !!
Conclusion : Trinomial can not be factored
Equation at the end of step 2 :
x6 - 1000x3 + 8000 = 0
Step 3 :
Solving a Single Variable Equation :
Equations which are reducible to quadratic :
3.1 Solve x6-1000x3+8000 = 0
This equation is reducible to quadratic. What this means is that using a new variable, we can rewrite this equation as a quadratic equation Using w , such that w = x3 transforms the equation into :
w2-1000w+8000 = 0
Solving this new equation using the quadratic formula we get two real solutions :
991.9350 or 8.0650
Now that we know the value(s) of w , we can calculate x since x is ∛ w
Doing just this we discover that the solutions of
x6-1000x3+8000 = 0
are either :
x = ∛991.935 = 9.9730
or:
x = ∛ 8.065 = 2.0054
Two solutions were found :
- x = ∛ 8.065 = 2.0054
- x = ∛991.935 = 9.9730
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