CBSE Class 10 Mathematics Standard 2023: question 22(b)

Hints

Open one hint at a time and try again before the next.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

1. From $\cos A+{\cos }^{2}A=1$:
   $\cos A=1-{\cos }^{2}A={\sin }^{2}A$ [since ${\sin }^{2}A+{\cos }^{2}A=1$]

   1 mark

2. Square this to get ${\sin }^{4}A={\cos }^{2}A$. Therefore
   ${\sin }^{2}A+{\sin }^{4}A=\cos A+{\cos }^{2}A=1$

   1 mark

Answer: ${\sin }^{2}A+{\sin }^{4}A=1$

Revise the chapter

• Chapter: Introduction to Trigonometry (notes, formulas, where marks are lost and every past question)
• Topic: Proving Simple Trigonometric Identities