Question

if sin @+ sin2@ = 1 then cis 2 @ + cos4@=​

Answer 1

Answer:

The value of cos²a+cos⁴a=1

Step-by-step explanation:

Given,

sin a+sin²a=1

Our starting goal is to turn all terms into cosine. Use the identity "sin²∅+cos²∅"

⇒sina+1-cos²a=1

⇒sina-cos²a=1

⇒sina=cos²a

Squaring on both sides

⇒(sina)²=(cos²a)²

⇒sin²a=cos⁴a

Reuse, sin²∅+cos²∅

⇒1-cos²a=cos⁴a

⇒cos²a=cos⁴a=1

Therefore, the value of "cos²a=cos⁴a=1"