What substitution should be used to rewrite 4x^4-21x^2+20=0 as a quadratic function?

Question

Mathematics

Koko

28 July, 08:42

What substitution should be used to rewrite 4x^4-21x^2+20=0 as a quadratic function?

+5

Answers (2)

Know the Answer?

Jordon Matthews · Answer 1

refer the explanation

Step-by-step explanation:

this question can be written as

X^2=y

so, x^4=y^2

so it will be 4y^2-21y+20=0

Kason Blevins · Answer 2

see explanation

Step-by-step explanation:

Let u = x² (choice of variable is flexible), then

4u² - 21u + 20 = 0 ← expressed as a quadratic

This can now be solved for u and converted back into terms of x