MCQ
One factor of $x^4 + x^2 - 20$ is $x^2 + 5.$ The other factor is:
- ✓$x^2 - 4$
- B$x - 4$
- C$x^{2 }- 5$
- D$x + 4$
✓
Answer
Correct option: A.
$x^2 - 4$
$x^4 + x^2 - 20$
$= x^4 + 5x^2 - 4x^2 - 20$
$=x^2(x^2 + 5) - 4(x^2 + 5)$
$= (x^2 + 5)(x^2 - 4)$
So, other factor is $x^2 - 4.$
$= x^4 + 5x^2 - 4x^2 - 20$
$=x^2(x^2 + 5) - 4(x^2 + 5)$
$= (x^2 + 5)(x^2 - 4)$
So, other factor is $x^2 - 4.$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The difference between two complementary angles is $400$. The angles are:
→The minimum value of a data is 82 and range is 38, then the maximum value is:
If a square paper of side $25\ cm$ is rolled to form a cylinder, then its curved surface area is.
→In Fig., if $l \ || \ m,$ then $x =$
→→
8 is a polynomial of degree.
The greatest chord of a circle is called its:
In the given figure, O is the centre of a circle and $\angle\text{AOB}=140^\circ.$ Then, $\angle\text{ACB}=?$
→- 70°
- 80°
- 110°
- 40°
A bag contains 16 cards bearing numbers 1, 2, 3, ..., 16 respectively. One card is chosen at random. What is the probability that the chosen card bears a number divisible by 3?
→- $\frac{3}{16}$
- $\frac{5}{16}$
- $\frac{11}{16}$
- $\frac{13}{16}$
The sum of $0.\overline{3}$ and $0.\overline{4}$ is:
→- $\frac{7}{10}$
- $\frac{7}{9}$
- $\frac{7}{11}$
- $\frac{7}{99}$