Q.16. The solutions to $7x^4 - 6x^2 + 1 = 0$ are $\pm \cos \theta$ and $\pm \cos \beta$.

Which one of the following equations has solutions $\pm \sin \theta$ and $\pm \sin \beta$ ?

Answer Choices

• $7x^4 - 8x^2 - 5 = 0$
• $7x^4 - 8x^2 + 2 = 0$
• $7x^4 - 6x^2 - 2 = 0$
• $7x^4 - 6x^2 + 1 = 0$
• $7x^4 + 6x^2 - 1 = 0$
• $7x^4 + 6x^2 + 5 = 0$

Solution

The correct answer is option 2: $7x^4 - 8x^2 + 2 = 0$.